A283051 Positive integers n such that none of the primes of the form k*2^n + 1 (with k odd) divide any Fermat number F(m) = 2^(2^m) + 1, m >= 0.

3, 5, 6, 10

Offset

1,1

Comments

Conjecture: sequence is infinite.

a(5) >= 18.

Links

Table of n, a(n) for n=1..4.

Proth Search Page, Prime factors of Fermat numbers

Eric Weisstein's World of Mathematics, Fermat Number

Crossrefs

Cf. A019434, A023394, A228845, A228846, A229857, A231203.

Sequence in context: A054871 A248644 A242197 * A376377 A244671 A232531

Adjacent sequences: A283048 A283049 A283050 * A283052 A283053 A283054

Keyword

nonn,hard,more

Author

Arkadiusz Wesolowski, Feb 27 2017

Status

approved