A050883 Numbers n such that 249*2^n-1 is prime.

8, 9, 12, 41, 57, 156, 201, 249, 612, 956, 1617, 2064, 2091, 2547, 4512, 5696, 9608, 11444, 20556, 33896, 77079, 89004, 251036

Offset

1,1

Links

Table of n, a(n) for n=1..23.

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

Kosmaj, Riesel list k<300.

Prog

(PARI) is(n)=ispseudoprime(249*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A063080 A167131 A109079 * A064164 A079525 A083131

Adjacent sequences: A050880 A050881 A050882 * A050884 A050885 A050886

Keyword

hard,nonn

Author

N. J. A. Sloane, Dec 29 1999

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

Status

approved