A053352 Numbers k such that 271*2^k + 1 is prime.

4, 84, 2164, 7780, 48100, 1165420

Offset

1,1

Links

Table of n, a(n) for n=1..6.

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[5*10^3], PrimeQ[271*2^# + 1] &] (* G. C. Greubel, May 24 2018 *)

Prog

(PARI) is(n)=ispseudoprime(271*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
(Magma) [n: n in [1..300] | IsPrime(271*2^n+1)];  // G. C. Greubel, May 24 2018

Crossrefs

Sequence in context: A203244 A245544 A361052 * A322330 A356504 A270577

Adjacent sequences: A053349 A053350 A053351 * A053353 A053354 A053355

Keyword

hard,nonn,more

Author

N. J. A. Sloane, Dec 29 1999

Extensions

a(6) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 20 2018

Status

approved