Smallest number k such that k+2^m is composite for all m less than k: Difference between revisions

=={{header|Python}}==

<syntaxhighlight lang="python">""" wiki/Smallest_number_k_such_that_k%2B2%5Em_is_composite_for_all_m_less_than_k """

from sympy import isprime

def a(k):

""" returns true if k is a sequence member, false otherwise """

if k == 1:

return False

for m in range(1, k):

n = 2**m + k

if isprime(n):

return False

return True

if __name__ == '__main__':

print([i for i in range(1, 5500, 2) if a(i)]) # [773, 2131, 2491, 4471, 5101]

</syntaxhighlight>{{out}}

[773, 2131, 2491, 4471, 5101]