A050593 Numbers k such that 135*2^k-1 is prime.

1, 9, 10, 13, 16, 21, 24, 34, 54, 153, 177, 184, 226, 238, 286, 334, 586, 618, 870, 3151, 3397, 4987, 5160, 14737, 15309, 15319, 16870, 29430, 39298, 40117, 56443, 58449, 77845, 105870, 127405, 170613, 183373, 235315, 245754

Offset

1,2

Links

Table of n, a(n) for n=1..39.

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[135*2^# - 1] & ] (* Robert Price, Dec 23 2018 *)

Prog

(PARI) is(n)=ispseudoprime(135*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A154766 A116594 A249723 * A189834 A248350 A247512

Adjacent sequences: A050590 A050591 A050592 * A050594 A050595 A050596

Keyword

hard,nonn,more

Author

N. J. A. Sloane, Dec 29 1999

Extensions

a(27)-a(39) from the Wilfrid Keller link by Robert Price, Dec 23 2018

Status

approved