A050903 Numbers n such that 289*2^n-1 is prime.

1, 3, 13, 21, 25, 33, 73, 93, 115, 127, 397, 1255, 3751, 3801, 4771, 8997, 10063, 11253, 18663, 27525, 28009, 34041, 55693, 60243, 67891, 77391, 90201, 501991, 509401

Offset

1,2

Comments

Also in the sequence: 610737, 728205, 1098117 - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

Links

Table of n, a(n) for n=1..29.

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(289*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A099502 A145024 A055059 * A117766 A243162 A147351

Adjacent sequences: A050900 A050901 A050902 * A050904 A050905 A050906

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