A050573 Numbers k such that 95*2^k-1 is prime.

2, 6, 26, 32, 66, 128, 170, 288, 320, 470, 1278, 1296, 1316, 1536, 1608, 13230, 15438, 31268, 42198, 46688, 71636, 140840, 259076, 271590, 790508

Offset

1,1

Links

Table of n, a(n) for n=1..25.

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

Kosmaj, Riesel list k<300.

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

Mathematica

Select[Range[1000], PrimeQ[95*2^# - 1] & ] (* Robert Price, Dec 23 2018 *)

Prog

(PARI) is(n)=ispseudoprime(95*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A348067 A032479 A029988 * A337573 A331963 A308988

Adjacent sequences: A050570 A050571 A050572 * A050574 A050575 A050576

Keyword

hard,nonn,more

Author

N. J. A. Sloane, Dec 29 1999

Extensions

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

a(25) from the Wilfrid Keller link by Robert Price, Dec 23 2018

Status

approved