A098856 - OEIS

%I #15 Aug 17 2024 23:01:46

%S 1,3,19,34,51,318,3670,6348,33292,48582,50235,50964

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

%C a(9) > 11500. - _Jinyuan Wang_, Mar 19 2020

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

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

%K nonn,more

%O 1,2

%A _Pierre CAMI_, Oct 11 2004

%E 6348, corresponding to a probable prime, from _Ryan Propper_, Jun 18 2005

%E Edited by _T. D. Noe_, Oct 30 2008

%E a(9)-a(12) from _Michael S. Branicky_, Aug 17 2024