A098856 Numbers k such that 4^k*(2^k - 1) + 1 is a prime.

1, 3, 19, 34, 51, 318, 3670, 6348

Offset

1,2

Comments

a(9) > 11500. - Jinyuan Wang, Mar 19 2020

Links

Table of n, a(n) for n=1..8.

Prog

(Magma) [k: k in [1..500] | IsPrime(4^k*(2^k-1)+1)]; // Jinyuan Wang, Mar 19 2020

Crossrefs

Cf. A098857 ((4^k)*(2^k - 1) - 1 is prime).

Sequence in context: A360081 A061427 A069516 * A178201 A062291 A106082

Adjacent sequences: A098853 A098854 A098855 * A098857 A098858 A098859

Keyword

nonn,more

Author

Pierre CAMI, Oct 11 2004

Extensions

6348, corresponding to a probable prime, from Ryan Propper, Jun 18 2005

Edited by T. D. Noe, Oct 30 2008

Status

approved