A032484 Numbers k such that 215*2^k+1 is prime.

1, 3, 171, 585, 1161, 1623, 5511, 7893, 11133, 12363, 25381, 67717, 146853, 260991, 953677

Offset

1,2

Links

Table of n, a(n) for n=1..15.

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[215*2^# + 1] & ] (* Robert Price, Dec 19 2018 *)

Prog

(PARI) is(n)=ispseudoprime(215*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A203482 A116506 A348704 * A119117 A136473 A209804

Adjacent sequences: A032481 A032482 A032483 * A032485 A032486 A032487

Keyword

nonn,hard,more

Author

N. J. A. Sloane.

Extensions

a(13)-a(15) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 19 2018

Status

approved