A322958 Numbers k such that 331*2^k+1 is prime.

4, 8, 12, 20, 28, 36, 120, 184, 200, 756, 788, 1304, 6412, 7848, 12944, 40116, 45056, 67520, 129172, 204592, 225568, 615116, 803668, 1646668

Offset

1,1

Links

Table of n, a(n) for n=1..24.

Ray Ballinger, Proth Search Page

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for 300 < k < 600

Y. Gallot, Proth.exe: Windows Program for Finding Large Primes

Wilfrid Keller, List of primes k.2^n - 1 for k < 300

Eric Weisstein's World of Mathematics, Proth Prime

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

Maple

select(n->isprime(331*2^n+1), [$1..1000]); # Muniru A Asiru, Dec 31 2018

Mathematica

Select[Range[1000], PrimeQ[331*2^# + 1] &] (* Robert Price, Dec 31 2018 *)

Crossrefs

Cf. A002255, A050527.

Sequence in context: A311662 A311663 A333572 * A123723 A279227 A261649

Adjacent sequences: A322955 A322956 A322957 * A322959 A322960 A322961

Keyword

nonn,more,hard

Author

Robert Price, Dec 31 2018

Status

approved