A032506 Numbers k such that 259*2^k+1 is prime.

38, 70, 3230, 62918, 82878, 1282582, 3094582, 4395550

Offset

1,1

Links

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

Ray Ballinger, Proth Search Page

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

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

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

Mathematica

Select[Range[1000], PrimeQ[259*2^# + 1] & ] (* Robert Price, Dec 20 2018 *)

Prog

(PARI) is(n)=ispseudoprime(259*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A343974 A335483 A071885 * A044104 A044485 A160846

Adjacent sequences: A032503 A032504 A032505 * A032507 A032508 A032509

Keyword

hard,nonn,more

Author

N. J. A. Sloane.

Extensions

a(6) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 20 2018

a(7)-a(8) from Jeppe Stig Nielsen, Dec 21 2024

Status

approved