A050845 Numbers n such that 187*2^n-1 is prime.

1, 17, 21, 53, 253, 2173, 3313, 5197, 5333, 6929, 28017, 40429, 47877, 80617, 110513, 139673, 141201, 263093, 379649, 483153

Offset

1,2

Links

Table of n, a(n) for n=1..20.

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(187*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A060875 A259555 A138600 * A219396 A125613 A147052

Adjacent sequences: A050842 A050843 A050844 * A050846 A050847 A050848

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