Special neighbor primes: Difference between revisions
add tinybasic
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Found 103611 special neighbour primes < 10^7
</pre>
=={{header|Tiny BASIC}}==
<lang tinybasic> REM B = SECOND OF THE NEIGBOURING PRIMES
REM C = P + B - 1
REM I = index variable
REM P = INPUT TO NEXTPRIME ROUTINE AND ISPRIME ROUTINE, also first of the two primes
REM T = Temporary variable, multiple uses
REM Z = OUTPUT OF ISPRIME, 1=prime, 0=not
LET P = 1
20 LET P = P + 2
IF P > 100 THEN END
GOSUB 100
IF Z = 0 THEN GOTO 20
GOSUB 120
IF B > 100 THEN END
LET T = P
LET P = P + B - 1
GOSUB 100
LET C = P
LET P = T
IF Z = 0 THEN GOTO 20
PRINT P," + ",B," - 1 = ", C
GOTO 20
100 REM PRIMALITY BY TRIAL DIVISION
LET Z = 1
LET I = 2
110 IF (P/I)*I = P THEN LET Z = 0
IF Z = 0 THEN RETURN
LET I = I + 1
IF I*I <= P THEN GOTO 110
RETURN
120 REM next prime after P
IF P < 2 THEN LET B = 2
IF P = 2 THEN LET B = 3
IF P < 3 THEN RETURN
LET T = P
130 LET P = P + 1
GOSUB 100
IF Z = 1 THEN GOTO 140
GOTO 130
140 LET B = P
LET P = T
RETURN</lang>
{{out}}<pre>
3 + 5 - 1 = 7
5 + 7 - 1 = 11
7 + 11 - 1 = 17
11 + 13 - 1 = 23
13 + 17 - 1 = 29
19 + 23 - 1 = 41
29 + 31 - 1 = 59
31 + 37 - 1 = 67
41 + 43 - 1 = 83
43 + 47 - 1 = 89
61 + 67 - 1 = 127
67 + 71 - 1 = 137
73 + 79 - 1 = 151</lang>
=={{header|Wren}}==
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