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Tau function (view source)

Revision as of 00:40, 21 March 2024

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Line 1:
{{draft task}}
[[Category:Mathematics]]
 
Line 6:
 
;Task
Show the result for the first   '''100'''   positive integers.
 
 
Line 12:
*  [[Tau number]]
<br><br>
 
=={{header|11l}}==
{{trans|Python}}
 
<syntaxhighlight lang="11l">F tau(n)
V ans = 0
V i = 1
V j = 1
L i * i <= n
I 0 == n % i
ans++
j = n I/ i
I j != i
ans++
i++
R ans
 
print((1..100).map(n -> tau(n)))</syntaxhighlight>
 
{{out}}
<pre>
[1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 6, 2, 4, 4, 5, 2, 6, 2, 6, 4, 4, 2, 8, 3, 4, 4, 6, 2, 8, 2, 6, 4, 4, 4, 9, 2, 4, 4, 8, 2, 8, 2, 6, 6, 4, 2, 10, 3, 6, 4, 6, 2, 8, 4, 8, 4, 4, 2, 12, 2, 4, 6, 7, 4, 8, 2, 6, 4, 8, 2, 12, 2, 4, 6, 6, 4, 8, 2, 10, 5, 4, 2, 12, 4, 4, 4, 8, 2, 12, 4, 6, 4, 4, 4, 12, 2, 6, 6, 9]
</pre>
=={{header|AArch64 Assembly}}==
{{works with|as|Raspberry Pi 3B version Buster 64 bits <br> or android 64 bits with application Termux }}
<syntaxhighlight lang="aarch64 assembly">
/* ARM assembly AARCH64 Raspberry PI 3B or android 64 bits */
/* program taufunction64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM64.inc"
.equ MAXI, 100
/*********************************/
/* Initialized data */
/*********************************/
.data
sMessResult: .asciz " @ "
szCarriageReturn: .asciz "\n"
/*********************************/
/* UnInitialized data */
/*********************************/
.bss
sZoneConv: .skip 24
/*********************************/
/* code section */
/*********************************/
.text
.global main
main: // entry of program
mov x0,#1 // factor number one
bl displayResult
mov x0,#2 // factor number two
bl displayResult
mov x2,#3 // begin number three
1: // begin loop
mov x5,#2 // divisor counter
mov x4,#2 // first divisor 1
2:
udiv x0,x2,x4 // compute divisor 2
msub x3,x0,x4,x2 // remainder
cmp x3,#0
bne 3f // remainder = 0 ?
cmp x0,x4 // same divisor ?
add x3,x5,1
add x6,x5,2
csel x5,x3,x6,eq
3:
add x4,x4,#1 // increment divisor
cmp x4,x0 // divisor 1 < divisor 2
blt 2b // yes -> loop
mov x0,x5 // equal -> display
bl displayResult
 
add x2,x2,1
cmp x2,MAXI // end ?
bls 1b // no -> loop
ldr x0,qAdrszCarriageReturn
bl affichageMess
100: // standard end of the program
mov x0, #0 // return code
mov x8, #EXIT // request to exit program
svc #0 // perform the system call
qAdrszCarriageReturn: .quad szCarriageReturn
/***************************************************/
/* display message number */
/***************************************************/
/* x0 contains the number */
displayResult:
stp x1,lr,[sp,-16]! // save registres
ldr x1,qAdrsZoneConv
bl conversion10 // call décimal conversion
strb wzr,[x1,x0]
ldr x0,qAdrsMessResult
ldr x1,qAdrsZoneConv // insert conversion in message
bl strInsertAtCharInc
bl affichageMess // display message
ldp x1,lr,[sp],16 // restaur des 2 registres
ret
qAdrsMessResult: .quad sMessResult
qAdrsZoneConv: .quad sZoneConv
/********************************************************/
/* File Include fonctions */
/********************************************************/
/* for this file see task include a file in language AArch64 assembly */
.include "../includeARM64.inc"
</syntaxhighlight>
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2
4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2 12 2
4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Action!}}==
<syntaxhighlight lang="action!">CARD FUNC DivisorCount(CARD n)
CARD result,p,count
result=1
WHILE (n&1)=0
DO
result==+1
n=n RSH 1
OD
 
p=3
WHILE p*p<=n
DO
count=1
WHILE n MOD p=0
DO
count==+1
n==/p
OD
result==*count
p==+2
OD
 
IF n>1 THEN
result==*2
FI
RETURN (result)
 
PROC Main()
CARD max=[100],n,divCount
 
PrintF("Tau function for the first %U numbers%E",max)
FOR n=1 TO max
DO
divCount=DivisorCount(n)
PrintC(divCount) Put(32)
OD
RETURN</syntaxhighlight>
{{out}}
[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Tau_function.png Screenshot from Atari 8-bit computer]
<pre>
Tau function for the first 100 numbers
 
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4
9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4
8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|ALGOL 68}}==
{{Trans|ALGOL W}}{{Trans|C++}}
<syntaxhighlight lang="algol68">BEGIN # find the count of the divisors of the first 100 positive integers #
# calculates the number of divisors of v #
PROC divisor count = ( INT v )INT:
BEGIN
INT total := 1, n := v;
# Deal with powers of 2 first #
WHILE NOT ODD n DO
total +:= 1;
n OVERAB 2
OD;
# Odd prime factors up to the square root #
FOR p FROM 3 BY 2 WHILE ( p * p ) <= n DO
INT count := 1;
WHILE n MOD p = 0 DO
count +:= 1;
n OVERAB p
OD;
total *:= count
OD;
# If n > 1 then it's prime #
IF n > 1 THEN total *:= 2 FI;
total
END # divisor_count # ;
BEGIN
INT limit = 100;
print( ( "Count of divisors for the first ", whole( limit, 0 ), " positive integers:" ) );
FOR n TO limit DO
IF n MOD 20 = 1 THEN print( ( newline ) ) FI;
print( ( whole( divisor count( n ), -4 ) ) )
OD
END
END</syntaxhighlight>
{{out}}
<pre>
Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|ALGOL-M}}==
<syntaxhighlight lang="ALGOL">
begin
 
% return the value of n mod m %
integer function mod(n, m);
integer n, m;
begin
mod := n - m * (n / m);
end;
 
% return the tau value (i.e, number of divisors) of n %
integer function tau(n);
integer n;
begin
integer i, t, limit;
if n < 3 then
t := n
else
begin
t := 2;
limit := (n + 1) / 2;
for i := 2 step 1 until limit do
begin
if mod(n, i) = 0 then t := t + 1;
end;
end;
tau := t;
end;
 
% test by printing the tau value of the first 100 numbers %
integer i;
write("Count of divisors for first 100 numbers:");
write("");
for i := 1 step 1 until 100 do
begin
writeon(tau(i));
if mod(i,10) = 0 then write(""); % print 10 across %
end;
 
end
</syntaxhighlight>
{{out}}
<pre>
Count of divisors for first 100 numbers:
1 2 2 3 2 4 2 4 3 4
2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8
2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6
4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8
2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9
</pre>
 
 
=={{header|ALGOL W}}==
{{Trans|C++}}
<langsyntaxhighlight algolwlang="pascal">begin % find the count of the divisors of the first 100 positive integers %
% calculates the number of divisors of v %
integer procedure divisor_count( integer value v ) ; begin
Line 37 ⟶ 308:
total := total * count
end while_p_x_p_le_n ;
% If n > 1 then it's is prime %
if n > 1 then total := total * 2;
total
Line 50 ⟶ 321:
end for_n
end
end.</langsyntaxhighlight>
{{out}}
<pre>
Line 60 ⟶ 331:
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|APL}}==
{{works with|Dyalog APL}}
<syntaxhighlight lang="apl">tau ← 0+.=⍳|⊢
tau¨ 5 20⍴⍳100</syntaxhighlight>
{{out}}
<pre>1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|AppleScript}}==
<langsyntaxhighlight lang="applescript">on factorCount(n)
if (n < 1) then return 0
set counter to 2
Line 85 ⟶ 367:
set output to output as text
set AppleScript's text item delimiters to astid
return output</langsyntaxhighlight>
 
{{output}}
<langsyntaxhighlight lang="applescript">"Positive divisor counts for integers 1 to 100:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9"</langsyntaxhighlight>
=={{header|ARM Assembly}}==
{{works with|as|Raspberry Pi <br> or android 32 bits with application Termux}}
<syntaxhighlight lang="arm assembly">
/* ARM assembly Raspberry PI */
/* program taufunction.s */
/* REMARK 1 : this program use routines in a include file
see task Include a file language arm assembly
for the routine affichageMess conversion10
see at end of this program the instruction include */
/* for constantes see task include a file in arm assembly */
/************************************/
/* Constantes */
/************************************/
.include "../constantes.inc"
.equ MAXI, 100
/*********************************/
/* Initialized data */
/*********************************/
.data
sMessResult: .asciz " @ "
szCarriageReturn: .asciz "\n"
/*********************************/
/* UnInitialized data */
/*********************************/
.bss
sZoneConv: .skip 24
/*********************************/
/* code section */
/*********************************/
.text
.global main
main: @ entry of program
mov r0,#1 @ factor number one
bl displayResult
mov r0,#2 @ factor number two
bl displayResult
mov r2,#3 @ begin number three
1: @ begin loop
mov r5,#2 @ divisor counter
mov r4,#2 @ first divisor 1
2:
udiv r0,r2,r4 @ compute divisor 2
mls r3,r0,r4,r2 @ remainder
cmp r3,#0
bne 3f @ remainder = 0 ?
cmp r0,r4 @ same divisor ?
addeq r5,r5,#1 @ yes increment one
addne r5,r5,#2 @ no increment two
3:
add r4,r4,#1 @ increment divisor
cmp r4,r0 @ divisor 1 < divisor 2
blt 2b @ yes -> loop
mov r0,r5 @ equal -> display
bl displayResult
 
add r2,#1 @
cmp r2,#MAXI @ end ?
bls 1b @ no -> loop
ldr r0,iAdrszCarriageReturn
bl affichageMess
100: @ standard end of the program
mov r0, #0 @ return code
mov r7, #EXIT @ request to exit program
svc #0 @ perform the system call
iAdrszCarriageReturn: .int szCarriageReturn
/***************************************************/
/* display message number */
/***************************************************/
/* r0 contains the number */
displayResult:
push {r1,r2,lr} @ save registers
ldr r1,iAdrsZoneConv
bl conversion10 @ call décimal conversion
mov r2,#0
strb r2,[r1,r0]
ldr r0,iAdrsMessResult
ldr r1,iAdrsZoneConv @ insert conversion in message
bl strInsertAtCharInc
bl affichageMess @ display message
pop {r1,r2,pc} @ restaur des registres
iAdrsMessResult: .int sMessResult
iAdrsZoneConv: .int sZoneConv
/***************************************************/
/* ROUTINES INCLUDE */
/***************************************************/
.include "../affichage.inc"
</syntaxhighlight>
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2
4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2
12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
=={{header|Arturo}}==
 
<syntaxhighlight lang="rebol">tau: function [x] -> size factors x
 
loop split.every:20 1..100 => [
print map & => [pad to :string tau & 3]
]</syntaxhighlight>
 
{{out}}
 
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Asymptote}}==
<syntaxhighlight lang="Asymptote">write("The tau functions for the first 100 positive integers are:");
for (int N = 1; N <= 100; ++N) {
int T;
if (N < 3) {
T = N;
} else {
T = 2;
for (int A = 2; A <= (N + 1) / 2; ++A) {
if (N % A == 0) T = T + 1;
}
}
write(format("%3d", T), suffix=none);
if (N % 10 == 0) write("");
}</syntaxhighlight>
 
=={{header|AutoHotkey}}==
<syntaxhighlight lang="autohotkey">loop 100
result .= SubStr(" " Tau(A_Index), -3) . (Mod(A_Index, 10) ? " " : "`n")
MsgBox % result
return
 
Tau(n){
return StrSplit(Factors(n), ",").Count()
}
Factors(n) {
Loop, % floor(sqrt(n))
v := A_Index = 1 ? 1 "," n : mod(n,A_Index) ? v : v "," A_Index "," n//A_Index
Sort, v, N U D,
Return, v
}</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4
2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8
2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6
4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8
2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|AWK}}==
<syntaxhighlight lang="awk">
<lang AWK>
# syntax: GAWK -f TAU_FUNCTION.AWK
BEGIN {
Line 116 ⟶ 555:
return(count)
}
</syntaxhighlight>
</lang>
{{out}}
<pre>
Line 131 ⟶ 570:
4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|BASIC}}==
{{trans|C}}
<syntaxhighlight lang="gwbasic">10 DEFINT A-Z
20 FOR I=1 TO 100
30 N=I: GOSUB 100
40 PRINT USING " ##";T;
50 IF I MOD 20=0 THEN PRINT
60 NEXT
70 END
100 T=1
110 IF (N AND 1)=0 THEN N=N\2: T=T+1: GOTO 110
120 P=3
130 GOTO 180
140 C=1
150 IF N MOD P=0 THEN N=N\P: C=C+1: GOTO 150
160 T=T*C
170 P=P+2
180 IF P*P<=N GOTO 140
190 IF N>1 THEN T=T*2
200 RETURN</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
 
==={{header|BASIC256}}===
<syntaxhighlight lang="basic256">print "The tau functions for the first 100 positive integers are:"
print
 
for N = 1 to 100
if N < 3 then
T = N
else
T = 2
for A = 2 to (N+1)\2
if N mod A = 0 then T += 1
next A
end if
print " "; T;
if N mod 10 = 0 then print
next N
end</syntaxhighlight>
 
==={{header|Gambas}}===
<syntaxhighlight lang="vbnet">Public Sub Main()
Print "The tau functions for the first 100 positive integers are:\n"
For i As Integer = 1 To 100
Print Format$(numdiv(i), "####");
If i Mod 10 = 0 Then Print
Next
End
 
Public Function numdiv(n As Integer) As Integer
 
Dim c As Integer = 1
For i As Integer = 1 To (n + 1) \ 2
If n Mod i = 0 Then c += 1
Next
If n = 1 Then c -= 1
Return c
 
End Function</syntaxhighlight>
{{out}}
<pre>Same as FreeBASIC entry.</pre>
 
==={{header|Chipmunk Basic}}===
{{works with|Chipmunk Basic|3.6.4}}
The [[#GW-BASIC|GW-BASIC]] solution works without any changes.
 
==={{header|MSX Basic}}===
{{works with|MSX BASIC|any}}
The [[#GW-BASIC|GW-BASIC]] solution works without any changes.
 
==={{header|QBasic}}===
{{works with|QBasic}}
<syntaxhighlight lang="qbasic">PRINT "The tau functions for the first 100 positive integers are:": PRINT
 
FOR N = 1 TO 100
IF N < 3 THEN
T = N
ELSE
T = 2
FOR A = 2 TO (N + 1) \ 2
IF N MOD A = 0 THEN T = T + 1
NEXT A
END IF
PRINT USING "###"; T;
IF N MOD 10 = 0 THEN PRINT
NEXT N
END</syntaxhighlight>
 
==={{header|Run BASIC}}===
{{works with|Just BASIC}}
{{works with|Liberty BASIC}}
<syntaxhighlight lang="vb">print "The tau functions for the first 100 positive integers are:"
print
for N = 1 to 100
if N < 3 then
T = N
else
T = 2
for A = 2 to int((N+1)/2)
if N mod A = 0 then T = T + 1
next A
end if
print using("####", T);
if N mod 10 = 0 then print
next N
end</syntaxhighlight>
 
==={{header|True BASIC}}===
<syntaxhighlight lang="qbasic">PRINT "The tau functions for the first 100 positive integers are:"
PRINT
 
FOR N = 1 TO 100
IF N < 3 THEN
LET T = N
ELSE
LET T = 2
FOR A = 2 TO INT((N+1)/2)
IF REMAINDER (N, A) = 0 THEN LET T = T + 1
NEXT A
END IF
PRINT " "; T;
IF REMAINDER (N, 10) = 0 THEN PRINT
NEXT N
END</syntaxhighlight>
 
==={{header|XBasic}}===
{{works with|Windows XBasic}}
<syntaxhighlight lang="qbasic">PROGRAM "Tau"
VERSION "0.0000"
 
DECLARE FUNCTION Entry ()
DECLARE FUNCTION numdiv(n)
 
FUNCTION Entry ()
PRINT "The tau functions for the first 100 positive integers are:\n"
FOR i = 1 TO 100
PRINT FORMAT$("###", numdiv(i));
IF i MOD 10 = 0 THEN PRINT
NEXT i
END FUNCTION
 
FUNCTION numdiv(n)
c = 1
FOR i = 1 TO (n+1)\2
IF n MOD i = 0 THEN INC c
NEXT i
IF n = 1 THEN DEC c
RETURN c
 
END FUNCTION
END PROGRAM</syntaxhighlight>
 
==={{header|Yabasic}}===
<syntaxhighlight lang="yabasic">print "The tau functions for the first 100 positive integers are:\n"
 
for N = 1 to 100
if N < 3 then
T = N
else
T = 2
for A = 2 to int((N+1)/2)
if mod(N, A) = 0 then T = T + 1 : fi
next A
end if
print T using "###";
if mod(N, 10) = 0 then print : fi
next N
end</syntaxhighlight>
 
=={{header|bc}}==
<syntaxhighlight lang="bc">define t(n) {
auto a, d, p
for (d = 1; n % 2 == 0; n /= 2) d += 1
for (p = 3; p * p <= n; p += 2) for (a = d; n % p == 0; n /= p) d += a
if (n != 1) d += d
return(d)
}
 
for (i = 1; i <= 100; ++i) t(i)</syntaxhighlight>
 
=={{header|BCPL}}==
<syntaxhighlight lang="bcpl">get "libhdr"
 
let tau(n) = valof
$( let total = 1 and p = 3
while (n & 1) = 0
$( total := total + 1
n := n >> 1
$)
while p*p <= n
$( let count = 1
while n rem p = 0
$( count := count + 1
n := n / p
$)
total := total * count
p := p + 2
$)
if n>1 then total := total * 2
resultis total
$)
 
let start() be
for n=1 to 100
$( writed(tau(n), 3)
if n rem 20 = 0 then wrch('*N')
$)</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|BQN}}==
<syntaxhighlight lang="bqn">Tau ← +´0=(1+↕)|⊢
Tau¨ 5‿20⥊1+↕100</syntaxhighlight>
{{out}}
<pre>┌─
╵ 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
┘</pre>
 
=={{header|C}}==
{{trans|C++}}
<syntaxhighlight lang="c">#include <stdio.h>
 
// See https://en.wikipedia.org/wiki/Divisor_function
unsigned int divisor_count(unsigned int n) {
unsigned int total = 1;
// Deal with powers of 2 first
for (; (n & 1) == 0; n >>= 1) {
++total;
}
// Odd prime factors up to the square root
for (unsigned int p = 3; p * p <= n; p += 2) {
unsigned int count = 1;
for (; n % p == 0; n /= p) {
++count;
}
total *= count;
}
// If n > 1 then it's prime
if (n > 1) {
total *= 2;
}
return total;
}
 
int main() {
const unsigned int limit = 100;
unsigned int n;
 
printf("Count of divisors for the first %d positive integers:\n", limit);
for (n = 1; n <= limit; ++n) {
printf("%3d", divisor_count(n));
if (n % 20 == 0) {
printf("\n");
}
}
 
return 0;
}</syntaxhighlight>
{{out}}
<pre>Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|C++}}==
<langsyntaxhighlight lang="cpp">#include <iomanip>
#include <iostream>
 
Line 163 ⟶ 884:
std::cout << '\n';
}
}</langsyntaxhighlight>
 
{{out}}
Line 173 ⟶ 894:
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Clojure}}==
{{trans|Raku}}
<syntaxhighlight lang="clojure">(require '[clojure.string :refer [join]])
(require '[clojure.pprint :refer [cl-format]])
 
(defn divisors [n] (filter #(zero? (rem n %)) (range 1 (inc n))))
 
(defn display-results [label per-line width nums]
(doall (map println (cons (str "\n" label ":") (list
(join "\n" (map #(join " " %)
(partition-all per-line (map #(cl-format nil "~v:d" width %) nums)))))))))
 
(display-results "Tau function - first 100" 20 3
(take 100 (map (comp count divisors) (drop 1 (range)))))
 
(display-results "Tau numbers – first 100" 10 5
(take 100 (filter #(zero? (rem % (count (divisors %)))) (drop 1 (range)))))
 
(display-results "Divisor sums – first 100" 20 4
(take 100 (map #(reduce + (divisors %)) (drop 1 (range)))))
 
(display-results "Divisor products – first 100" 5 16
(take 100 (map #(reduce * (divisors %)) (drop 1 (range)))))</syntaxhighlight>
 
{{Out}}
<pre>
 
Tau function - first 100:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
 
Tau numbers – first 100:
1 2 8 9 12 18 24 36 40 56
60 72 80 84 88 96 104 108 128 132
136 152 156 180 184 204 225 228 232 240
248 252 276 288 296 328 344 348 360 372
376 384 396 424 441 444 448 450 468 472
480 488 492 504 516 536 560 564 568 584
600 612 625 632 636 640 664 672 684 708
712 720 732 776 792 804 808 824 828 852
856 864 872 876 880 882 896 904 936 948
972 996 1,016 1,040 1,044 1,048 1,056 1,068 1,089 1,096
 
Divisor sums – first 100:
1 3 4 7 6 12 8 15 13 18 12 28 14 24 24 31 18 39 20 42
32 36 24 60 31 42 40 56 30 72 32 63 48 54 48 91 38 60 56 90
42 96 44 84 78 72 48 124 57 93 72 98 54 120 72 120 80 90 60 168
62 96 104 127 84 144 68 126 96 144 72 195 74 114 124 140 96 168 80 186
121 126 84 224 108 132 120 180 90 234 112 168 128 144 120 252 98 171 156 217
 
Divisor products – first 100:
1 2 3 8 5
36 7 64 27 100
11 1,728 13 196 225
1,024 17 5,832 19 8,000
441 484 23 331,776 125
676 729 21,952 29 810,000
31 32,768 1,089 1,156 1,225
10,077,696 37 1,444 1,521 2,560,000
41 3,111,696 43 85,184 91,125
2,116 47 254,803,968 343 125,000
2,601 140,608 53 8,503,056 3,025
9,834,496 3,249 3,364 59 46,656,000,000
61 3,844 250,047 2,097,152 4,225
18,974,736 67 314,432 4,761 24,010,000
71 139,314,069,504 73 5,476 421,875
438,976 5,929 37,015,056 79 3,276,800,000
59,049 6,724 83 351,298,031,616 7,225
7,396 7,569 59,969,536 89 531,441,000,000
8,281 778,688 8,649 8,836 9,025
782,757,789,696 97 941,192 970,299 1,000,000,000
</pre>
 
 
=={{header|CLU}}==
{{trans|C}}
<syntaxhighlight lang="clu">tau = proc (n: int) returns (int)
total: int := 1
while n//2 = 0 do
total := total + 1
n := n/2
end
p: int := 3
while p*p <= n do
count: int := 1
while n//p = 0 do
count := count + 1
n := n/p
end
total := total * count
p := p+2
end
if n>1 then
total := total * 2
end
return(total)
end tau
 
start_up = proc ()
po: stream := stream$primary_output()
for n: int in int$from_to(1, 100) do
stream$putright(po, int$unparse(tau(n)), 3)
if n//20=0 then stream$putl(po, "") end
end
end start_up</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|COBOL}}==
{{trans|C}}
<syntaxhighlight lang="cobol"> IDENTIFICATION DIVISION.
PROGRAM-ID. TAU-FUNCTION.
 
DATA DIVISION.
WORKING-STORAGE SECTION.
01 TAU-VARS.
03 TOTAL PIC 999.
03 N PIC 999.
03 FILLER REDEFINES N.
05 FILLER PIC 99.
05 FILLER PIC 9.
88 N-EVEN VALUES 0, 2, 4, 6, 8.
03 P PIC 999.
03 P-SQUARED PIC 999.
03 N-DIV-P PIC 999V999.
03 FILLER REDEFINES N-DIV-P.
05 NEXT-N PIC 999.
05 FILLER PIC 999.
88 DIVISIBLE VALUE ZERO.
03 F-COUNT PIC 999.
01 CONTROL-VARS.
03 I PIC 999.
01 OUT-VARS.
03 OUT-ITM PIC ZZ9.
03 OUT-STR PIC X(80) VALUE SPACES.
03 OUT-PTR PIC 99 VALUE 1.
 
PROCEDURE DIVISION.
BEGIN.
PERFORM SHOW-TAU VARYING I FROM 1 BY 1
UNTIL I IS GREATER THAN 100.
STOP RUN.
SHOW-TAU.
MOVE I TO N.
PERFORM TAU.
MOVE TOTAL TO OUT-ITM.
STRING OUT-ITM DELIMITED BY SIZE INTO OUT-STR
WITH POINTER OUT-PTR.
IF OUT-PTR IS EQUAL TO 61,
DISPLAY OUT-STR,
MOVE 1 TO OUT-PTR.
 
TAU.
MOVE 1 TO TOTAL.
PERFORM POWER-OF-2 UNTIL NOT N-EVEN.
MOVE ZERO TO P-SQUARED.
PERFORM ODD-FACTOR THRU ODD-FACTOR-LOOP
VARYING P FROM 3 BY 2
UNTIL P-SQUARED IS GREATER THAN N.
IF N IS GREATER THAN 1,
MULTIPLY 2 BY TOTAL.
POWER-OF-2.
ADD 1 TO TOTAL.
DIVIDE 2 INTO N.
ODD-FACTOR.
MULTIPLY P BY P GIVING P-SQUARED.
MOVE 1 TO F-COUNT.
ODD-FACTOR-LOOP.
DIVIDE N BY P GIVING N-DIV-P.
IF DIVISIBLE,
MOVE NEXT-N TO N,
ADD 1 TO F-COUNT,
GO TO ODD-FACTOR-LOOP.
MULTIPLY F-COUNT BY TOTAL.</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Cowgol}}==
{{trans|C}}
<syntaxhighlight lang="cowgol">include "cowgol.coh";
 
typedef N is uint8;
sub tau(n: N): (total: N) is
total := 1;
while n & 1 == 0 loop
total := total + 1;
n := n >> 1;
end loop;
var p: N := 3;
while p*p <= n loop
var count: N := 1;
while n%p == 0 loop
count := count + 1;
n := n / p;
end loop;
total := total * count;
p := p + 2;
end loop;
if n>1 then
total := total << 1;
end if;
end sub;
 
sub print2(n: uint8) is
print_char(' ');
if n<10
then print_char(' ');
else print_i8(n/10);
end if;
print_i8(n%10);
end sub;
 
var n: N := 1;
while n <= 100 loop
print2(tau(n));
if n % 20 == 0 then print_nl(); end if;
n := n + 1;
end loop;</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|D}}==
{{trans|C++}}
<syntaxhighlight lang="d">import std.stdio;
 
// See https://en.wikipedia.org/wiki/Divisor_function
uint divisor_count(uint n) {
uint total = 1;
// Deal with powers of 2 first
for (; (n & 1) == 0; n >>= 1) {
++total;
}
// Odd prime factors up to the square root
for (uint p = 3; p * p <= n; p += 2) {
uint count = 1;
for (; n % p == 0; n /= p) {
++count;
}
total *= count;
}
// If n > 1 then it's prime
if (n > 1) {
total *= 2;
}
return total;
}
 
void main() {
immutable limit = 100;
writeln("Count of divisors for the first ", limit, " positive integers:");
for (uint n = 1; n <= limit; ++n) {
writef("%3d", divisor_count(n));
if (n % 20 == 0) {
writeln;
}
}
}</syntaxhighlight>
{{out}}
<pre>Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Dart}}==
{{trans|C++}}
<syntaxhighlight lang="dart">int divisorCount(int n) {
int total = 1;
// Deal with powers of 2 first
for (; (n & 1) == 0; n >>= 1) total++;
// Odd prime factors up to the square root
for (int p = 3; p * p <= n; p += 2) {
int count = 1;
for (; n % p == 0; n ~/= p) count++;
total *= count;
}
// If n > 1 then it's prime
if (n > 1) total *= 2;
return total;
}
 
void main() {
const int limit = 100;
print("Count of divisors for the first $limit positive integers:");
for (int n = 1; n <= limit; ++n) {
print(divisorCount(n).toString().padLeft(3));
}
}</syntaxhighlight>
 
=={{header|Delphi}}==
{{libheader| System.SysUtils}}
{{Trans|Go}}
<syntaxhighlight lang="delphi">
program Tau_function;
 
{$APPTYPE CONSOLE}
 
uses
System.SysUtils;
 
function CountDivisors(n: Integer): Integer;
begin
Result := 0;
var i := 1;
var k := 2;
if (n mod 2) = 0 then
k := 1;
 
while i * i <= n do
begin
if (n mod i) = 0 then
begin
inc(Result);
var j := n div i;
if j <> i then
inc(Result);
end;
inc(i, k);
end;
end;
 
begin
writeln('The tau functions for the first 100 positive integers are:');
for var i := 1 to 100 do
begin
write(CountDivisors(i): 2, ' ');
if (i mod 20) = 0 then
writeln;
end;
readln;
end.</syntaxhighlight>
 
=={{header|Draco}}==
<syntaxhighlight lang="draco">proc nonrec tau(word n) word:
word count, total, p;
total := 1;
while n & 1 = 0 do
total := total + 1;
n := n >> 1
od;
p := 3;
while p*p <= n do
count := 1;
while n % p = 0 do
count := count + 1;
n := n / p
od;
total := total * count;
p := p + 2
od;
if n>1
then total << 1
else total
fi
corp
 
proc nonrec main() void:
byte n;
for n from 1 upto 100 do
write(tau(n):3);
if n%20=0 then writeln() fi
od
corp</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Dyalect}}==
 
{{trans|Swift}}
 
<syntaxhighlight lang="dyalect">func divisorCount(number) {
var n = number
var total = 1
while (n &&& 1) == 0 {
total += 1
n >>>= 1
}
var p = 3
while p * p <= n {
var count = 1
while n % p == 0 {
count += 1
n /= p
}
total *= count
p += 2
}
if n > 1 {
total *= 2
}
total
}
let limit = 100
print("Count of divisors for the first \(limit) positive integers:")
for n in 1..limit {
print(divisorCount(number: n).ToString().PadLeft(2, ' ') + " ", terminator: "")
print() when n % 20 == 0
}</syntaxhighlight>
 
{{out}}
 
<pre>Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9 </pre>
 
=={{header|EasyLang}}==
<syntaxhighlight>
func cntdiv n .
i = 1
while i <= sqrt n
if n mod i = 0
cnt += 1
if i <> n div i
cnt += 1
.
.
i += 1
.
return cnt
.
for i to 100
write cntdiv i & " "
.
</syntaxhighlight>
 
=={{header|EMal}}==
{{trans|Java}}
<syntaxhighlight lang="emal">
fun divisorCount = int by int n
int total = 1
for ; (n & 1) == 0; n /= 2 do ++total end
for int p = 3; p * p <= n; p += 2
int count = 1
for ; n % p == 0; n /= p do ++count end
total *= count
end
if n > 1 do total *= 2 end
return total
end
int limit = 100
writeLine("Count of divisors for the first " + limit + " positive integers:")
for int n = 1; n <= limit; ++n
text value = text!divisorCount(n)
write((" " * (3 - value.length)) + value)
if n % 20 == 0 do writeLine() end
end
</syntaxhighlight>
{{out}}
<pre>
Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|F_Sharp|F#}}==
This task uses [[Extensible_prime_generator#The_functions|Extensible Prime Generator (F#)]].<br>
<syntaxhighlight lang="fsharp">
// Tau function. Nigel Galloway: March 10th., 2021
let tau u=let P=primes32()
let rec fN g=match u%g with 0->g |_->fN(Seq.head P)
let rec fG n i g e l=match n=u,u%l with (true,_)->e |(_,0)->fG (n*i) i g (e+g)(l*i) |_->let q=fN(Seq.head P) in fG (n*q) q e (e+e) (q*q)
let n=Seq.head P in fG 1 n 1 1 n
[1..100]|>Seq.iter(tau>>printf "%d "); printfn ""
</syntaxhighlight>
{{out}}
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Factor}}==
{{works with|Factor|0.99 2020-08-14}}
<langsyntaxhighlight lang="factor">USING: assocs formatting io kernel math math.primes.factors
math.ranges sequences sequences.extras ;
 
Line 193 ⟶ 1,415:
[ "%2d |" printf ]
[ dup 10 + [a,b) [ tau "%4d" printf ] each nl ] bi
] each</langsyntaxhighlight>
{{out}}
<pre>
Line 211 ⟶ 1,433:
91 | 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Fermat}}==
<syntaxhighlight lang="text">Func Tau(t) =
if t<3 then Return(t) else
numdiv:=2;
for q = 2 to t\2 do
if Divides(q, t) then numdiv:=numdiv+1 fi;
od;
Return(numdiv);
fi;
.;
 
for i = 1 to 100 do
!(Tau(i),' ');
od;</syntaxhighlight>
{{out}}<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Forth}}==
{{trans|C++}}
<langsyntaxhighlight lang="forth">: divisor_count ( n -- n )
1 >r
begin
Line 246 ⟶ 1,485:
 
100 print_divisor_counts
bye</langsyntaxhighlight>
 
{{out}}
Line 259 ⟶ 1,498:
 
=={{header|FreeBASIC}}==
<langsyntaxhighlight lang="freebasic">function numdiv( n as uinteger ) as uinteger
dim as uinteger c = 1
for i as uinteger = 1 to (n+1)\2
Line 271 ⟶ 1,510:
print numdiv(i),
if i mod 10 = 0 then print
next i</langsyntaxhighlight>
{{out}}
<pre>1 2 2 3 2 4 2 4 3 4
Line 283 ⟶ 1,522:
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Frink}}==
<syntaxhighlight lang="frink">tau[n] := length[allFactors[n]]
 
for n=1 to 100
print[tau[n] + " "]
println[]</syntaxhighlight>
{{out}}
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Go}}==
<langsyntaxhighlight lang="go">package main
 
import "fmt"
Line 317 ⟶ 1,567:
}
}
}</langsyntaxhighlight>
 
{{out}}
Line 330 ⟶ 1,580:
 
=={{header|GW-BASIC}}==
<langsyntaxhighlight lang="gwbasic">10 FOR N = 1 TO 100
20 IF N < 3 THEN T=N: GOTO 70
30 T=2
Line 338 ⟶ 1,588:
70 PRINT T;
80 IF N MOD 10 = 0 THEN PRINT
90 NEXT N</langsyntaxhighlight>
{{out}}
<pre>
Line 351 ⟶ 1,601:
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Haskell}}==
<syntaxhighlight lang="haskell">tau :: Integral a => a -> a
tau n | n <= 0 = error "Not a positive integer"
tau n = go 0 (1, 1)
where
yo i = (i, i * i)
go r (i, ii)
| n < ii = r
| n == ii = r + 1
| 0 == mod n i = go (r + 2) (yo $ i + 1)
| otherwise = go r (yo $ i + 1)
 
main = print $ map tau [1..100]</syntaxhighlight>
{{out}}
<pre>[1,2,2,3,2,4,2,4,3,4,2,6,2,4,4,5,2,6,2,6,4,4,2,8,3,4,4,6,2,8,2,6,4,4,4,9,2,4,4,8,2,8,2,6,6,4,2,10,3,6,4,6,2,8,4,8,4,4,2,12,2,4,6,7,4,8,2,6,4,8,2,12,2,4,6,6,4,8,2,10,5,4,2,12,4,4,4,8,2,12,4,6,4,4,4,12,2,6,6,9]</pre>
 
 
Or using primeFactors from the Data.Numbers.Primes library:
 
<syntaxhighlight lang="haskell">import Data.Numbers.Primes
import Data.List (group, intercalate, transpose)
import Data.List.Split (chunksOf)
import Text.Printf
 
----------------------- OEISA000005 ----------------------
 
oeisA000005 :: [Int]
oeisA000005 = tau <$> [1..]
 
tau :: Integer -> Int
tau = product . fmap (succ . length) . group . primeFactors
 
 
--------------------------- TEST -------------------------
 
main :: IO ()
main = putStrLn $
(table " " . chunksOf 10 . fmap show . take 100)
oeisA000005
 
 
------------------------ FORMATTING ----------------------
 
table :: String -> [[String]] -> String
table gap rows =
let ws = maximum . fmap length <$> transpose rows
pw = printf . flip intercalate ["%", "s"] . show
in unlines $ intercalate gap . zipWith pw ws <$> rows</syntaxhighlight>
 
{{Out}}
<pre>1 2 2 3 2 4 2 4 3 4
2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8
2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6
4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8
2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|J}}==
<syntaxhighlight lang="j">tau =: [:+/0=>:@i.|]
echo tau"0 [5 20$>:i.100
exit ''</syntaxhighlight>
{{out}}
<pre>1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Java}}==
{{trans|D}}
<syntaxhighlight lang="java">public class TauFunction {
private static long divisorCount(long n) {
long total = 1;
// Deal with powers of 2 first
for (; (n & 1) == 0; n >>= 1) {
++total;
}
// Odd prime factors up to the square root
for (long p = 3; p * p <= n; p += 2) {
long count = 1;
for (; n % p == 0; n /= p) {
++count;
}
total *= count;
}
// If n > 1 then it's prime
if (n > 1) {
total *= 2;
}
return total;
}
 
public static void main(String[] args) {
final int limit = 100;
System.out.printf("Count of divisors for the first %d positive integers:\n", limit);
for (long n = 1; n <= limit; ++n) {
System.out.printf("%3d", divisorCount(n));
if (n % 20 == 0) {
System.out.println();
}
}
}
}</syntaxhighlight>
{{out}}
<pre>Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|jq}}==
{{works with|jq}}
'''Works with gojq, the Go implementation of jq'''
 
'''Preliminaries'''
See https://rosettacode.org/wiki/Sum_of_divisors#jq for the definition of `divisors` used here.<syntaxhighlight lang="jq">def count(s): reduce s as $x (0; .+1);
 
# For pretty-printing
def nwise($n):
def n: if length <= $n then . else .[0:$n] , (.[$n:] | n) end;
n;
 
def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] + .;</syntaxhighlight>
'''The task'''
<syntaxhighlight lang="jq">[range(1;101) | count(divisors)]
| nwise(10) | map(lpad(4)) | join("")</syntaxhighlight>
{{out}}
<pre>
1 2 2 3 2 4 2 4 3 4
2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8
2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6
4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8
2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Julia}}==
Recycles code from http://www.rosettacode.org/wiki/Sequence:_smallest_number_greater_than_previous_term_with_exactly_n_divisors#Julia
<langsyntaxhighlight lang="julia">using Primes
 
function numfactors(n)
Line 368 ⟶ 1,763:
print(rpad(numfactors(i), 3), i % 25 == 0 ? " \n" : " ")
end
</langsyntaxhighlight>{{out}}
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3
Line 375 ⟶ 1,770:
6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Lua}}==
{{trans|Java}}
<syntaxhighlight lang="lua">function divisorCount(n)
local total = 1
-- Deal with powers of 2 first
while (n & 1) == 0 do
total = total + 1
n = math.floor(n / 2)
end
-- Odd prime factors up tot eh square root
local p = 3
while p * p <= n do
local count = 1
while n % p == 0 do
count = count + 1
n = n / p
end
total = total * count
p = p + 2
end
-- If n > 1 then it's prime
if n > 1 then
total = total * 2
end
return total
end
 
limit = 100
print("Count of divisors for the first " .. limit .. " positive integers:")
for n=1,limit do
io.write(string.format("%3d", divisorCount(n)))
if n % 20 == 0 then
print()
end
end</syntaxhighlight>
{{out}}
<pre>Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Mathematica}}/{{header|Wolfram Language}}==
<syntaxhighlight lang="mathematica">DivisorSum[#, 1 &] & /@ Range[100]</syntaxhighlight>
{{out}}
<pre>{1,2,2,3,2,4,2,4,3,4,2,6,2,4,4,5,2,6,2,6,4,4,2,8,3,4,4,6,2,8,2,6,4,4,4,9,2,4,4,8,2,8,2,6,6,4,2,10,3,6,4,6,2,8,4,8,4,4,2,12,2,4,6,7,4,8,2,6,4,8,2,12,2,4,6,6,4,8,2,10,5,4,2,12,4,4,4,8,2,12,4,6,4,4,4,12,2,6,6,9}</pre>
 
=={{header|MiniScript}}==
<syntaxhighlight lang="miniscript">
tau = function(n)
ans = 0
i = 1
while i * i <= n
if n % i == 0 then
ans += 1
j = floor(n / i)
if j != i then ans += 1
end if
i += 1
end while
return ans
end function
 
taus = []
for n in range(1, 100)
taus.push(tau(n))
end for
 
print taus.join(", ")
</syntaxhighlight>
{{out}}
<pre>
1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 6, 2, 4, 4, 5, 2, 6, 2, 6, 4, 4, 2, 8, 3, 4, 4, 6, 2, 8, 2, 6, 4, 4, 4, 9, 2, 4, 4, 8, 2, 8, 2, 6, 6, 4, 2, 10, 3, 6, 4, 6, 2, 8, 4, 8, 4, 4, 2, 12, 2, 4, 6, 7, 4, 8, 2, 6, 4, 8, 2, 12, 2, 4, 6, 6, 4, 8, 2, 10, 5, 4, 2, 12, 4, 4, 4, 8, 2, 12, 4, 6, 4, 4, 4, 12, 2, 6, 6, 9
</pre>
 
=={{header|Modula-2}}==
{{trans|C}}
<syntaxhighlight lang="modula2">MODULE TauFunc;
FROM InOut IMPORT WriteCard, WriteLn;
 
VAR i: CARDINAL;
 
PROCEDURE tau(n: CARDINAL): CARDINAL;
VAR total, count, p: CARDINAL;
BEGIN
total := 1;
WHILE n MOD 2 = 0 DO
n := n DIV 2;
total := total + 1
END;
p := 3;
WHILE p*p <= n DO
count := 1;
WHILE n MOD p = 0 DO
n := n DIV p;
count := count + 1
END;
total := total * count;
p := p + 2
END;
IF n>1 THEN total := total * 2 END;
RETURN total;
END tau;
 
BEGIN
FOR i := 1 TO 100 DO
WriteCard(tau(i), 3);
IF i MOD 20 = 0 THEN WriteLn END
END
END TauFunc.</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Nim}}==
<syntaxhighlight lang="nim">import math, strutils
 
func divcount(n: Natural): Natural =
for i in 1..sqrt(n.toFloat).int:
if n mod i == 0:
inc result
if n div i != i: inc result
 
echo "Count of divisors for the first 100 positive integers:"
for i in 1..100:
stdout.write ($divcount(i)).align(3)
if i mod 20 == 0: echo()</syntaxhighlight>
 
{{out}}
<pre>Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|PARI/GP}}==
<langsyntaxhighlight lang="parigp">vector(100,X,numdiv(X))</langsyntaxhighlight>
{{out}}<pre>
[1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 6, 2, 4, 4, 5, 2, 6, 2, 6, 4, 4, 2, 8, 3, 4, 4, 6, 2, 8, 2, 6, 4, 4, 4, 9, 2, 4, 4, 8, 2, 8, 2, 6, 6, 4, 2, 10, 3, 6, 4, 6, 2, 8, 4, 8, 4, 4, 2, 12, 2, 4, 6, 7, 4, 8, 2, 6, 4, 8, 2, 12, 2, 4, 6, 6, 4, 8, 2, 10, 5, 4, 2, 12, 4, 4, 4, 8, 2, 12, 4, 6, 4, 4, 4, 12, 2, 6, 6, 9]</pre>
 
=={{header|Pascal}}==
{{works with|Extended Pascal}}
<syntaxhighlight lang="pascal">program tauFunction(output);
 
type
{ name starts with `integer…` to facilitate sorting in documentation }
integerPositive = 1..maxInt value 1;
{ the `value …` will initialize all variables to this value }
 
{ returns Boolean value of the expression divisor ∣ dividend ----------- }
function divides(
protected divisor: integerPositive;
protected dividend: integer
): Boolean;
begin
{ in Pascal, function result variable has the same name as function }
divides := dividend mod divisor = 0
end;
 
{ returns τ(i) --------------------------------------------------------- }
function tau(protected i: integerPositive): integerPositive;
var
count, potentialDivisor: integerPositive;
begin
{ count is initialized to 1 and every number is divisible by one }
for potentialDivisor := 2 to i do
begin
count := count + ord(divides(potentialDivisor, i))
end;
{ in Pascal, there must be exactly one assignment to result variable }
tau := count
end;
 
{ === MAIN ============================================================= }
var
i: integerPositive;
f: string(6);
begin
for i := 1 to 100 do
begin
writeStr(f, 'τ(', i:1);
writeLn(f:8, ') = ', tau(i):5)
end
end.</syntaxhighlight>
==={{header|Free Pascal}}===
{{works with|Free Pascal}} and on TIO.RUN. Only test 0..99 for a nicer table.
<syntaxhighlight lang="pascal">program Tau_function;
{$IFDEF Windows} {$APPTYPE CONSOLE} {$ENDIF}
function CountDivisors(n: NativeUint): integer;
var
q, p, cnt, divcnt: NativeUint;
begin
divCnt := 1;
if n > 1 then
begin
cnt := 1;
while not (Odd(n)) do
begin
n := n shr 1;
divCnt := divCnt+cnt;
end;
p := 3;
while p * p <= n do
begin
cnt := divCnt;
q := n div p;
while q * p = n do
begin
n := q;
q := n div p;
divCnt := divCnt+cnt;
end;
Inc(p, 2);
end;
if n <> 1 then
divCnt := divCnt+divCnt;
end;
CountDivisors := divCnt;
end;
 
const
UPPERLIMIT = 99;
colWidth = trunc(ln(UPPERLIMIT)/ln(10))+1;
var
i: NativeUint;
begin
writeln('The tau functions for the first ',UPPERLIMIT,' positive integers are:');
Write('': colWidth+1);
for i := 0 to 9 do
Write(i: colWidth, ' ');
for i := 0 to UPPERLIMIT do
begin
if i mod 10 = 0 then
begin
writeln;
Write(i div 10: colWidth, '|');
end;
Write(CountDivisors(i): colWidth, ' ');
end;
writeln;
{$Ifdef Windows}readln;{$ENDIF}
end.</syntaxhighlight>
{{out|TIO.RUN}}
<pre>
The tau functions for the first 99 positive integers are:
0 1 2 3 4 5 6 7 8 9
0| 1 1 2 2 3 2 4 2 4 3
1| 4 2 6 2 4 4 5 2 6 2
2| 6 4 4 2 8 3 4 4 6 2
3| 8 2 6 4 4 4 9 2 4 4
4| 8 2 8 2 6 6 4 2 10 3
5| 6 4 6 2 8 4 8 4 4 2
6|12 2 4 6 7 4 8 2 6 4
7| 8 2 12 2 4 6 6 4 8 2
8|10 5 4 2 12 4 4 4 8 2
9|12 4 6 4 4 4 12 2 6 6 </pre>
 
=={{header|Perl}}==
{{libheader|ntheory}}
<langsyntaxhighlight lang="perl">use strict;
use warnings;
use feature 'say';
Line 392 ⟶ 2,045:
 
say "Tau function - first 100:\n" .
((sprintf "@{['%4d' x 100]}", @x[0..100-1]) =~ s/(.{80})/$1\n/gr);</langsyntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
Line 402 ⟶ 2,055:
=={{header|Phix}}==
=== imperative ===
<!--<syntaxhighlight lang="phix">(phixonline)-->
<lang Phix>for i=1 to 100 do
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">100</span> <span style="color: #008080;">do</span>
printf(1,"%3d",{length(factors(i,1))})
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%3d"</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">factors</span><span style="color: #0000FF;">(</span><span style="color: #000000;">i</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">))})</span>
if remainder(i,20)=0 then puts(1,"\n") end if
<span style="color: #008080;">if</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">i</span><span style="color: #0000FF;">,</span><span style="color: #000000;">20</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end for</lang>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
Line 416 ⟶ 2,071:
=== functional ===
same output
<!--<syntaxhighlight lang="phix">(phixonline)-->
<lang Phix>sequence r = apply(apply(true,factors,{tagset(100),{1}}),length)
<span style="color: #004080;">sequence</span> <span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">factors</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">100</span><span style="color: #0000FF;">),{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}}),</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">)</span>
puts(1,join_by(apply(true,sprintf,{{"%3d"},r}),1,20,""))</lang>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">join_by</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">,{{</span><span style="color: #008000;">"%3d"</span><span style="color: #0000FF;">},</span><span style="color: #000000;">r</span><span style="color: #0000FF;">}),</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">20</span><span style="color: #0000FF;">,</span><span style="color: #008000;">""</span><span style="color: #0000FF;">))</span>
<!--</syntaxhighlight>-->
 
=={{header|PL/I}}==
{{trans|C}}
<syntaxhighlight lang="pli">taufunc: procedure options(main);
tau: procedure(nn) returns(fixed);
declare (n, nn, tot, pf, cnt) fixed;
tot = 1;
do n=nn repeat(n/2) while(mod(n,2)=0);
tot = tot + 1;
end;
do pf=3 repeat(pf+2) while(pf*pf<=n);
do cnt=1 repeat(cnt+1) while(mod(n,pf)=0);
n = n/pf;
end;
tot = tot * cnt;
end;
if n>1 then tot = tot * 2;
return(tot);
end tau;
 
declare n fixed;
do n=1 to 100;
put edit(tau(n)) (F(3));
if mod(n,20)=0 then put skip;
end;
end taufunc;</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
 
=={{header|PL/M}}==
{{trans|C}}
<syntaxhighlight lang="pli">100H:
 
/* CP/M BDOS FUNCTIONS */
BDOS: PROCEDURE(F,A); DECLARE F BYTE, A ADDRESS; GO TO 5; END BDOS;
EXIT: PROCEDURE; GO TO 0; END EXIT;
PR$CHAR: PROCEDURE(C); DECLARE C BYTE; CALL BDOS(2,C); END PR$CHAR;
PR$STR: PROCEDURE(S); DECLARE S ADDRESS; CALL BDOS(9,S); END PR$STR;
 
/* PRINT BYTE IN A 3-CHAR COLUMN */
PRINT3: PROCEDURE(N);
DECLARE (N, M) BYTE;
M = 100;
DO WHILE M>0;
IF N>=M
THEN CALL PR$CHAR('0' + (N/M) MOD 10);
ELSE CALL PR$CHAR(' ');
M = M/10;
END;
END PRINT3;
 
/* TAU FUNCTION */
TAU: PROCEDURE(N) BYTE;
DECLARE (N, TOTAL, COUNT, P) BYTE;
TOTAL = 1;
DO WHILE NOT N;
N = SHR(N,1);
TOTAL = TOTAL + 1;
END;
P = 3;
DO WHILE P*P <= N;
COUNT = 1;
DO WHILE N MOD P = 0;
COUNT = COUNT + 1;
N = N / P;
END;
TOTAL = TOTAL * COUNT;
P = P + 2;
END;
IF N>1 THEN TOTAL = SHL(TOTAL, 1);
RETURN TOTAL;
END TAU;
 
/* PRINT TAU 1..100 */
DECLARE N BYTE;
DO N=1 TO 100;
CALL PRINT3(TAU(N));
IF N MOD 20=0 THEN CALL PR$STR(.(13,10,'$'));
END;
CALL EXIT;
EOF</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|PureBasic}}==
<syntaxhighlight lang="purebasic">If OpenConsole()
For i=1 To 100
If i<3 : Print(RSet(Str(i),4)) : Continue :EndIf
c=2
For j=2 To i/2+1 : c+Bool(i%j=0) : Next
Print(RSet(Str(c),4))
If i%10=0 : PrintN("") : EndIf
Next
Input()
EndIf
End</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4
2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8
2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6
4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8
2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Python}}==
===Using prime factorization===
<langsyntaxhighlight Pythonlang="python">def factorize(n):
assert(isinstance(n, int))
if n < 0:
Line 453 ⟶ 2,226:
 
if __name__ == "__main__":
print([*map(tau(n) for n in, range(1, 101)]))</langsyntaxhighlight>
===Finding divisors efficiently===
<langsyntaxhighlight Pythonlang="python">def tau(n):
assert(isinstance(n, int) and 0 < n)
ans,t i,= j(n = 0,- 1, 1^ n).bit_length()
whilen i*i <>>= n:t - 1
p if 0 == n%i:3
while p * p ans +<= 1n:
ja = n//it
while n % p if j !== i0:
anst += 1a
i + n //= 1p
return ans p += 2
if n != 1:
t += t
return t
 
if __name__ == "__main__":
print([*map(tau(n) for n in, range(1, 101)]))</langsyntaxhighlight>
{{out}}
<pre>[1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 6, 2, 4, 4, 5, 2, 6, 2, 6, 4, 4, 2, 8, 3, 4, 4, 6, 2, 8, 2, 6, 4, 4, 4, 9, 2, 4, 4, 8, 2, 8, 2, 6, 6, 4, 2, 10, 3, 6, 4, 6, 2, 8, 4, 8, 4, 4, 2, 12, 2, 4, 6, 7, 4, 8, 2, 6, 4, 8, 2, 12, 2, 4, 6, 6, 4, 8, 2, 10, 5, 4, 2, 12, 4, 4, 4, 8, 2, 12, 4, 6, 4, 4, 4, 12, 2, 6, 6, 9]</pre>
 
===Choosing the right abstraction===
Yet another exercise in defining a '''divisors''' function.
 
<langsyntaxhighlight lang="python">'''The number of divisors of n'''
 
from itertools import count, islice
Line 561 ⟶ 2,337:
# MAIN ---
if __name__ == '__main__':
main()</langsyntaxhighlight>
{{Out}}
<pre> 1 2 2 3 2 4 2 4 3 4
Line 573 ⟶ 2,349:
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9</pre>
 
=={{header|Quackery}}==
 
<code>factors</code> is defined at [[Factors of an integer#Quackery]].
 
 
<syntaxhighlight lang="quackery"> [ factors size ] is tau ( n --> n )
 
[] []
100 times [ i^ 1+ tau join ]
witheach [ number$ nested join ]
70 wrap$
</syntaxhighlight>
 
{{out}}
 
<pre>1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4
9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4
8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|R}}==
This only takes one line.
<syntaxhighlight lang="rsplus">lengths(sapply(1:100, function(n) c(Filter(function(x) n %% x == 0, seq_len(n %/% 2)), n)))</syntaxhighlight>
 
=={{header|Racket}}==
<syntaxhighlight lang="racket">
#lang racket
 
(define limit 100)
 
(define (divisor-count n)
(length (filter (λ (x) (zero? (remainder n x))) (range 1 (add1 n)))))
 
(printf "Count of divisors of the integers from 1 to ~a are~n" limit)
(for ([n (in-range 1 (add1 limit))])
(printf (~a (divisor-count n) #:width 5 #:align 'right))
(when (zero? (remainder n 10))
(newline)))
</syntaxhighlight>
{{out}}
<pre>
Count of divisors of the integers from 1 to 100 are
1 2 2 3 2 4 2 4 3 4
2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8
2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6
4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8
2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Raku}}==
Yet more tasks that are tiny variations of each other. [[Tau function]], [[Tau number]], [[Sum of divisors]] and [[Product of divisors]] all use code with minimal changes. What the heck, post 'em all.
 
<syntaxhighlight lang="raku" perl6line>use Prime::Factor:ver<0.3.0+>;
use Lingua::EN::Numbers;
 
Line 594 ⟶ 2,424:
say "\nDivisor products - first 100:\n", # ID
(1..*).map({ [×] .&divisors })[^100]\ # the task
.batch(5)».&comma».fmt("%16s").join("\n"); # display formatting</langsyntaxhighlight>
{{out}}
<pre>Tau function - first 100:
Line 645 ⟶ 2,475:
 
=={{header|REXX}}==
<langsyntaxhighlight lang="rexx">/*REXX program counts the number of divisors (tau, or sigma_0) up to and including N.*/
parse arg n . LO HI cols . /*obtain optional argument from the CL.*/
if n LO=='' | n LO=="," then n LO= 100 1 /*Not specified? Then use the default.*/
if HI=='' | HI=="," then HI= LO + 100 - 1 /*Not specified? Then use the default.*/
say 'the number of divisors (tau) for integers up to ' n " (inclusive):"; say
if cols=='' | cols=="," then cols= 20 /* " " " " " " */
say '─index─' center(" tau (number of divisors) ", 80, '─')
w= max(7,2 + length(nHI>45359) ) /*W: used to align 1stthe output columncolumns. */
$=say 'The number of divisors (tau) for integers up to ' n " /*$(inclusive):"; the output list, shown 20/line. */say
say '─index─' center(" tau (number of divisors) ", cols * (w+1) + 1, '─')
do j=1 for n /*list # proper divisors (tau) 1 ──► N */
$=; $= $ || right( tau(j), 4) /*add a tau number to c= 0 /*$: the output list., shown ROW/line.*/
ifdo j//20\==0LO thento iterateHI; c= c + 1 /*Notlist # aproper multipledivisors of(tau) 20?1 ──► Don'tN display.*/
say$= center$ right( tau(j-19), 7w) $; $= /*displayadd partiala listtau number to the terminaloutput list. */
if c//cols \== 0 then iterate /*Not a multiple of ROW? Don't display.*/
idx= j - cols + 1 /*calculate index value (for this row).*/
say center(idx, 7) $; $= /*display partial list to the terminal.*/
end /*j*/
 
if $\=='' then say center(j-1idx+cols, 7) $ /*there any residuals left to display ? */
exit 0 /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
Line 673 ⟶ 2,506:
end /* ___ */
else if j*j>x then leave /*only divide up to √ x */
end /*j*/; return # /* [↑] this form of DO loop is faster.*/</langsyntaxhighlight>
{{out|output|text=&nbsp; when using the default input:}}
<pre>
theThe number of divisors (tau) for integers up to 100 (inclusive):
 
─index─ ──────────────────────────── tau (number of divisors) ────────────────────────────
─index─ ─────────────────────────── tau (number of divisors) ───────────────────────────
1 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
21 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
Line 687 ⟶ 2,520:
 
=={{header|Ring}}==
<langsyntaxhighlight lang="ring">
see "The tau functions for the first 100 positive integers are:" + nl
 
Line 711 ⟶ 2,544:
see "" + tau + " "
end
</syntaxhighlight>
</lang>
Output:
<pre>
Line 726 ⟶ 2,559:
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|RPL}}==
{{trans|Python}}
{{works with|Halcyon Calc|4.2.7}}
{| class="wikitable"
! RPL Code
! Python code
|-
|
≪ → n
≪ 0 1
1 n √ '''FOR''' ii
'''IF''' n ii MOD NOT '''THEN'''
SWAP 1 + SWAP
DROP n ii / IP
'''IF''' DUP ii ≠
'''THEN''' SWAP 1 + SWAP '''END END'''
'''NEXT'''
DROP
≫ ≫ ‘TAU’ STO
|
''(n -- tau(n) )''
ans, j = 0, 1
while i*i <= n:
if 0 == n%i:
ans += 1
j = n//i
if j != i:
ans += 1
i += 1
return ans
.
|}
The following line of command delivers what is required:
≪ {} 1 100 '''FOR''' j j TAU + '''NEXT''' ≫ EVAL
{{out}}
<pre>
1: { 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9 }
</pre>
===Optimized algorithm===
{| class="wikitable"
! RPL code
! Comment
|-
|
≪
DUP √ DUP FP 0 -1 '''IFTE'''
1 ROT '''FOR''' j
OVER j MOD NOT DUP + +
'''NEXT''' SWAP DROP
≫ ‘TAU’ STO
|
''( n -- tau(n) )''
counter set at -1 if n square, 0 otherwise
while j ≤ n²
add 2 to counter for each dividing j
forget n
|}
 
=={{header|Ruby}}==
<syntaxhighlight lang="ruby">require 'prime'
 
def tau(n) = n.prime_division.inject(1){|res, (d, exp)| res *= exp + 1}
 
(1..100).map{|n| tau(n).to_s.rjust(3) }.each_slice(20){|ar| puts ar.join}
</syntaxhighlight>
{{out}}
<pre> 1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Rust}}==
<syntaxhighlight lang="rust">// returns the highest power of i that is a factor of n,
// and n divided by that power of i
fn factor_exponent(n: i32, i: i32) -> (i32, i32) {
if n % i == 0 {
let (a, b) = factor_exponent(n / i, i);
(a + 1, b)
} else {
(0, n)
}
}
 
fn tau(n: i32) -> i32 {
for i in 2..(n+1) {
if n % i == 0 {
let (count, next) = factor_exponent(n, i);
return (count + 1) * tau(next);
}
}
return 1;
}
 
fn main() {
for i in 1..101 {
print!("{} ", tau(i));
}
}</syntaxhighlight>
Output:
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|S-BASIC}}==
<syntaxhighlight lang="BASIC">
rem - return the value of n mod m
function mod(n, m = integer) = integer
end = n - m * (n / m)
 
rem - return the tau value (number of divisors) of n
function tau(n = integer) = integer
var i, t, limit = integer
if n < 3 then
t = n
else
begin
t = 2
limit = (n + 1) / 2
for i = 2 to limit
if mod(n, i) = 0 then t = t + 1
next i
end
end = t
 
rem - test by printing the tau value of the first 100 numbers
var i = integer
print "Number of divisors for first 100 numbers:"
for i = 1 to 100
print using "## "; tau(i);
if mod(i, 10) = 0 then print
next i
 
end
</syntaxhighlight>
{{out}}
<pre>
Number of divisors for first 100 numbers:
1 2 2 3 2 4 2 4 3 4
2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8
2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6
4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8
2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12
4 6 4 4 4 12 2 6 6 9
</pre>
 
 
=={{header|Scala}}==
{{trans|Java}}
<syntaxhighlight lang="Scala">
object TauFunction {
 
private def divisorCount(n: Long): Long = {
var count = 1L
var number = n
 
// Deal with powers of 2 first
while ((number & 1L) == 0) {
count += 1
number >>= 1
}
 
// Odd prime factors up to the square root
var p = 3L
while (p * p <= number) {
var tempCount = 1L
while (number % p == 0) {
tempCount += 1
number /= p
}
count *= tempCount
p += 2
}
 
// If n > 1 then it's prime
if (number > 1) {
count *= 2
}
 
count
}
 
def main(args: Array[String]): Unit = {
val limit = 100
println(s"Count of divisors for the first $limit positive integers:")
for (n <- 1 to limit) {
print(f"${divisorCount(n)}%3d")
if (n % 20 == 0) println()
}
}
}
</syntaxhighlight>
{{out}}
<pre>
Count of divisors for the first 100 positive integers:
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
 
</pre>
 
=={{header|Sidef}}==
Built-in:
<syntaxhighlight lang="ruby">say { .sigma0 }.map(1..100).join(' ')</syntaxhighlight>
 
{{out}}
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6 4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8 2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12 2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10 5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|Swift}}==
<langsyntaxhighlight lang="swift">import Foundation
 
// See https://en.wikipedia.org/wiki/Divisor_function
Line 765 ⟶ 2,817:
print()
}
}</langsyntaxhighlight>
 
{{out}}
Line 778 ⟶ 2,830:
 
=={{header|Tiny BASIC}}==
<langsyntaxhighlight lang="tinybasic"> LET N = 0
10 LET N = N + 1
IF N < 3 THEN GOTO 100
Line 790 ⟶ 2,842:
END
100 LET T = N
GOTO 30</langsyntaxhighlight>
 
 
=={{header|Verilog}}==
<syntaxhighlight lang="verilog">module main;
integer N, T, A;
initial begin
$display("The tau functions for the first 100 positive integers are:\n");
for (N = 1; N <= 100; N=N+1) begin
if (N < 3) T = N;
else begin
T = 2;
for (A = 2; A <= (N+1)/2; A=A+1) begin
if (N % A == 0) T = T + 1;
end
end
$write(T);
if (N % 10 == 0) $display("");
end
$finish ;
end
endmodule</syntaxhighlight>
 
=={{header|Wren}}==
{{libheader|Wren-math}}
{{libheader|Wren-fmt}}
<langsyntaxhighlight ecmascriptlang="wren">import "./math" for Int
import "./fmt" for Fmt
 
System.print("The tau functions for the first 100 positive integers are:")
Line 802 ⟶ 2,877:
Fmt.write("$2d ", Int.divisors(i).count)
if (i % 20 == 0) System.print()
}</langsyntaxhighlight>
 
{{out}}
Line 812 ⟶ 2,887:
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
 
=={{header|XPL0}}==
<syntaxhighlight lang="xpl0">int N, D, C;
[Format(3, 0);
for N:= 1 to 100 do
[C:= 0;
for D:= 1 to N do
if rem(N/D) = 0 then C:= C+1;
RlOut(0, float(C));
if rem(N/20) = 0 then CrLf(0);
];
]</syntaxhighlight>
 
{{out}}
<pre>
1 2 2 3 2 4 2 4 3 4 2 6 2 4 4 5 2 6 2 6
4 4 2 8 3 4 4 6 2 8 2 6 4 4 4 9 2 4 4 8
2 8 2 6 6 4 2 10 3 6 4 6 2 8 4 8 4 4 2 12
2 4 6 7 4 8 2 6 4 8 2 12 2 4 6 6 4 8 2 10
5 4 2 12 4 4 4 8 2 12 4 6 4 4 4 12 2 6 6 9
</pre>
Jjuanhdez
2,130

edits

Retrieved from "https://rosettacode.org/wiki/Special:MobileDiff/305496...362356"