A058781 Numbers k such that k^2 * 2^k - 1 is prime.

3, 7, 25, 41, 45, 63, 83, 131, 147, 175, 425, 449, 469, 651, 1345, 1839, 1883, 1913, 2177, 2551, 2907, 3675, 6071, 11743, 14641, 38685, 40857, 47761, 97243

Offset

1,1

Comments

If it exists, a(30) > 200000. - Hugo Pfoertner, Nov 07 2023

Links

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

Steven Harvey, Generalized HyperWoodall Primes

Mathematica

Do[ If[ PrimeQ[ n^2*2^n - 1 ], Print[n] ], {n, 1, 5000} ]

Prog

(PARI) is(n)=ispseudoprime(n^2*2^n-1) \\ Charles R Greathouse IV, May 22 2017

Crossrefs

Cf. A058780.

Sequence in context: A157817 A118718 A349753 * A347614 A363535 A100462

Adjacent sequences: A058778 A058779 A058780 * A058782 A058783 A058784

Keyword

nonn

Author

Robert G. Wilson v, Jan 02 2001

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008

Status

approved