A050907 Numbers k such that 297*2^k-1 is prime.

1, 2, 4, 8, 9, 10, 14, 18, 24, 25, 30, 42, 48, 49, 56, 90, 97, 182, 336, 348, 434, 546, 769, 1148, 1294, 1394, 1654, 2265, 2966, 3608, 4201, 4878, 5449, 7944, 8889, 9114, 10508, 11224, 15706, 17730, 18564, 21122, 21806, 21882, 24462, 24602, 29384, 35306

Offset

1,2

Links

Robert Price, Table of n, a(n) for n = 1..61

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

Maple

select(n->isprime(297*2^n-1), [$1..1000]); # Muniru A Asiru, Dec 30 2018

Mathematica

Select[Range[1000], PrimeQ[297*2^# - 1] & ] (* Robert Price, Dec 30 2018 *)

Prog

(PARI) is(n)=ispseudoprime(297*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A049642 A326713 A328945 * A100675 A196730 A325942

Adjacent sequences: A050904 A050905 A050906 * A050908 A050909 A050910

Keyword

hard,nonn

Author

N. J. A. Sloane, Dec 29 1999

Extensions

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

a(49)-a(61) from the Wilfrid Keller link by Robert Price, Dec 30 2018

Status

approved