A053366 Numbers k such that 299*2^k + 1 is prime.

1, 3, 7, 9, 45, 57, 73, 79, 81, 91, 141, 177, 193, 241, 267, 493, 777, 921, 1167, 1179, 1191, 1689, 2389, 4635, 5377, 9487, 13573, 15781, 26017, 31977, 40455, 59487, 64417, 70441, 85263, 366103, 1692271, 2070979, 3130621, 4333939

Offset

1,2

Links

Table of n, a(n) for n=1..40.

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[5*10^3], PrimeQ[299*2^# + 1] &] (* G. C. Greubel, May 25 2018 *)

Prog

(PARI) is(n)=ispseudoprime(299*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
(Magma) [n: n in [1..3000] | IsPrime(299*2^n+1)]; // G. C. Greubel, May 25 2018

Crossrefs

Sequence in context: A075982 A100839 A013624 * A128052 A033681 A074339

Adjacent sequences: A053363 A053364 A053365 * A053367 A053368 A053369

Keyword

hard,nonn,more,changed

Author

N. J. A. Sloane, Dec 29 1999

Extensions

a(36)-a(37) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 22 2018

a(38) from Jeppe Stig Nielsen, May 31 2020

a(39)-a(40) from Jeppe Stig Nielsen, Dec 20 2024

Status

approved