Numbers whose count of divisors is prime: Difference between revisions

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{{Draft task}}
{{Draft task}}


;Task:Find numbers which count of divisors is prime, where '''n < 200'''
;Task:Find numbers which count of divisors is prime but not equal to 2, where '''n < 1.000'''


<br><br>
<br><br>
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see "Numbers which count of divisors is prime are:" + nl
see "Numbers which count of divisors is prime are:" + nl


for n = 1 to 200
for n = 1 to 1000
num = 0
num = 0
for m = 1 to n
for m = 1 to n
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ok
ok
next
next
if isprime(num)
if isprime(num) and num != 2
see "" + n + " "
see "" + n + " "
row++
row++
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next
next


see nl + "Found " + row + " numbers" + nl
see "done..." + nl
see "done..." + nl
</lang>
</lang>
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working...
working...
Numbers which count of divisors is prime are:
Numbers which count of divisors is prime are:
2 3 4 5 7
4 9 16 25 49
9 11 13 16 17
64 81 121 169 289
19 23 25 29 31
361 529 625 729 841
961
37 41 43 47 49
Found 16 numbers
53 59 61 64 67
71 73 79 81 83
89 97 101 103 107
109 113 121 127 131
137 139 149 151 157
163 167 169 173 179
181 191 193 197 199
done...
done...
</pre>
</pre>

Revision as of 03:12, 11 July 2021

Numbers whose count of divisors is prime is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.
Task
Find numbers which count of divisors is prime but not equal to 2, where n < 1.000



Ring

<lang ring> load "stdlib.ring" row = 0

see "working..." + nl see "Numbers which count of divisors is prime are:" + nl

for n = 1 to 1000 

   num = 0
   for m = 1 to n
       if n%m = 0
          num++
       ok
   next
   if isprime(num) and num != 2
      see "" + n + " "
      row++
      if row%5 = 0
         see nl
      ok
   ok

next

see nl + "Found " + row + " numbers" + nl see "done..." + nl </lang>

Output:
working...
Numbers which count of divisors is prime are:
4 9 16 25 49 
64 81 121 169 289 
361 529 625 729 841 
961 
Found 16 numbers
done...
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