A032461 Numbers k such that 169*2^k+1 is prime.

2, 14, 26, 158, 282, 298, 406, 522, 534, 1050, 1470, 1478, 1614, 1970, 2570, 5054, 5166, 6238, 9614, 14026, 49602, 63686, 70110, 76934, 109666, 167734, 223590, 602070, 801578, 1327114, 1635086, 2545526

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Ray Ballinger, Proth Search Page

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

Mathematica

Select[Range[1000], PrimeQ[169*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)

Prog

(PARI) is(n)=ispseudoprime(169*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A109080 A295083 A180877 * A072390 A213136 A117705

Adjacent sequences: A032458 A032459 A032460 * A032462 A032463 A032464

Keyword

nonn,hard,more

Author

N. J. A. Sloane.

Extensions

a(23)-a(31) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018

a(32) from Jeppe Stig Nielsen, Apr 04 2020

Status

approved