Smallest number k such that k+2^m is composite for all m less than k: Difference between revisions
Smallest number k such that k+2^m is composite for all m less than k (view source)
Revision as of 18:34, 31 March 2024
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=={{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]
=={{header|Raku}}==
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