A050890 Numbers k such that 263*2^k-1 is prime.

2, 6, 26, 114, 134, 180, 542, 882, 936, 2382, 3702, 5082, 6722, 15590, 19910, 26964, 29148, 48062, 54870, 69642, 73788, 79922, 95460, 215712

Offset

1,1

Links

Table of n, a(n) for n=1..24.

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(263*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A282618 A192435 A296217 * A114710 A230245 A358107

Adjacent sequences: A050887 A050888 A050889 * A050891 A050892 A050893

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