A377248 Numbers k such that 8191 * 2^k + 1 is prime.

12, 20, 412, 712, 2092, 4704, 10176, 33396, 41124, 105604, 139780, 142924

Offset

1,1

Comments

8191 is the 5th Mersenne prime: 8191 = 2^13 - 1 (a term of A000668).

Links

Table of n, a(n) for n=1..12.

Example

12 is a term, because 8191 * 2^12 + 1 = 8191 * 4096 + 1 = 33550337 is prime. (also a term of A061644).

Prog

(PARI) is(k) = isprime(8191 * 2^k + 1);

Crossrefs

Cf. A000668, A002253, A002254, A001771, A061644.

Sequence in context: A167351 A231400 A231467 * A078600 A076638 A129939

Adjacent sequences: A377245 A377246 A377247 * A377249 A377250 A377251

Keyword

nonn,more

Author

Arsen Vardanyan, Oct 21 2024

Extensions

a(8)-a(9) from Hugo Pfoertner, Oct 21 2024

a(10)-a(12) from Michael S. Branicky, Nov 05 2024

Status

approved