A032463 Numbers k such that 173*2^k+1 is prime.

1, 13, 6253, 23313, 77289, 135033, 349149, 604585, 1099741, 1673881, 2199301, 2578197, 2729905

Offset

1,2

Links

Table of n, a(n) for n=1..13.

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

Mathematica

Select[Range[1000], PrimeQ[173*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)

Prog

(PARI) is(n)=ispseudoprime(173*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A185674 A103857 A263160 * A298273 A203585 A191937

Adjacent sequences: A032460 A032461 A032462 * A032464 A032465 A032466

Keyword

nonn,hard,more

Author

N. J. A. Sloane.

Extensions

a(6)-a(10) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018

a(11)-a(13) from Jeppe Stig Nielsen, Mar 12 2020

Status

approved