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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. 0
3, 5, 6, 10 (list; graph; refs; listen; history; text; internal format)
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 * A244671 A232531 A182637

Adjacent sequences:  A283048 A283049 A283050 * A283052 A283053 A283054

KEYWORD

nonn,hard,more

AUTHOR

Arkadiusz Wesolowski, Feb 27 2017

STATUS

approved

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Last modified February 17 12:14 EST 2020. Contains 331996 sequences. (Running on oeis4.)