A032407 Numbers k such that 115*2^k+1 is prime.

2, 12, 20, 26, 42, 114, 228, 396, 456, 482, 1298, 3048, 4968, 7568, 28004, 32466, 40548, 66576, 78588, 101016, 120650, 157488, 292730, 778112, 1338620

Offset

1,1

Links

Table of n, a(n) for n=1..25.

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

Ray Ballinger, Proth Search Page

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

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[115*2^# + 1] & ] (* Robert Price, Dec 17 2018 *)

Prog

(PARI) is(n)=ispseudoprime(115*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A305162 A339709 A137311 * A136725 A023534 A286683

Adjacent sequences: A032404 A032405 A032406 * A032408 A032409 A032410

Keyword

nonn,more

Author

James R. Buddenhagen

Extensions

Extended by Hugo Pfoertner, Jul 02 2003

a(22)-a(25) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 17 2018

Status

approved