View source for Find numbers n in base 2 where n is prime and all it's digits are 1

{{Draft task}}

;Task:
Find numbers n in base 2 where n is prime and all it's digits are 1
<br>Let 1 < n < 10000

=={{header|Factor}}==
Numbers in base 2 whose digits are all 1: also known as the powers of 2 minus 1.
<lang factor>USING: lists lists.lazy math math.primes prettyprint ;

2 lfrom [ 2^ 1 - ] <lazy-map> [ prime? ] lfilter [ 10,000 < ] lwhile list>array .</lang>
{{out}}
<pre>
{ 3 7 31 127 8191 }
</pre>

=={{header|Ring}}==
<lang ring>
load "stdlib.ring"

num = 0
limit = 6
decList = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]
baseList = ["0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"]

see "working..." + nl
see "the first 5 elements of sequence are:" + nl

for n = 1 to 10000 
    if isprime(n)
       flag = 1
       bn = decimaltobase(n,2)
       for m = 1 to len(bn)
           if not(bn[m] = "1") 
              flag = 0
              exit
           ok
       next
       if flag = 1
          num = num + 1
          if num < limit
             see "" + num + ". " + "number = " + n + " in base 2 = " + bn + nl
          ok
       ok
    ok
next

see "done..." + nl

func decimaltobase(nr,base)
     binList = [] 
     binary = 0
     remainder = 1
     while(nr != 0)
          remainder = nr % base
          ind = find(decList,remainder)
          rem = baseList[ind]
          add(binList,rem)
          nr = floor(nr/base) 
     end
     binlist = reverse(binList)
     binList = list2str(binList)
     binList = substr(binList,nl,"")  
     return binList
</lang>
{{out}}
<pre>
working...
the first 5 elements of sequence are:
1. number = 3 in base 2 = 11
2. number = 7 in base 2 = 111
3. number = 31 in base 2 = 11111
4. number = 127 in base 2 = 1111111
5. number = 8191 in base 2 = 1111111111111
done...

</pre>