Mersenne primes: Difference between revisions

=={{header|Ring}}==

<lang ring>

# Project : Mersenne primes

# Date : 2018/01/22

# Author : Gal Zsolt [~ CalmoSoft ~]

# Email : <calmosoft@gmail.com>

n = 0

while true

n = n +1

if isprime(pow(2,n)-1) = 1

see n + nl

ok

end

func isprime num

if (num <= 1) return 0 ok

if (num % 2 = 0) and num != 2 return 0 ok

for i = 3 to floor(num / 2) -1 step 2

if (num % i = 0) return 0 ok

next

return 1

</lang>

Output:

<pre>

2

3

5

7

13

17

19

</pre>