A268661 Numbers n such that 5*2^n + 1 is a prime factor of a generalized Fermat number 3^(2^m) + 1 for some m.

3, 55, 127, 13165, 240937, 819739, 1282755

Offset

1,1

References

Wilfrid Keller, private communication, 2008.

Links

Table of n, a(n) for n=1..7.

Anders Björn and Hans Riesel, Factors of generalized Fermat numbers, Math. Comp. 67 (1998), no. 221, pp. 441-446.

Anders Björn and Hans Riesel, Table errata to “Factors of generalized Fermat numbers”, Math. Comp. 74 (2005), no. 252, p. 2099.

Anders Björn and Hans Riesel, Table errata 2 to "Factors of generalized Fermat numbers", Math. Comp. 80 (2011), pp. 1865-1866.

C. K. Caldwell, Top Twenty page, Generalized Fermat Divisors (base=3)

OEIS Wiki, Generalized Fermat numbers

Crossrefs

Cf. A059919, A268662, A268663, A226366, A268664, A268657, A268658, A204620, A268659, A268660. Subsequence of A002254.

Sequence in context: A340214 A088278 A242199 * A041155 A111483 A119152

Adjacent sequences: A268658 A268659 A268660 * A268662 A268663 A268664

Keyword

nonn,hard,more

Author

Arkadiusz Wesolowski, Feb 10 2016

Status

approved