A188936 Numbers k such that (2^k + 3)^2 - 8 is prime.

1, 2, 3, 4, 5, 6, 8, 10, 11, 12, 19, 27, 28, 32, 36, 48, 56, 61, 131, 170, 251, 750, 771, 779, 790, 874, 1176, 1728, 2604, 3541, 5394, 6203, 9230, 14666, 15680, 26712, 45840, 46019, 56220

Offset

1,2

Links

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

Daniel Shanks, Gauss's ternary form reduction and the 2-Sylow subgroup, Math. Comp. 25 (1971), 837-853.

Prog

(PARI) for(n=1, 10^6, if(isprime((2^n+3)^2-8), print1(n, ", "))); /* Joerg Arndt, Apr 25 2011 */

Crossrefs

Cf. A188129, A188661, A188937.

Sequence in context: A087721 A226244 A140642 * A260317 A072666 A075471

Adjacent sequences: A188933 A188934 A188935 * A188937 A188938 A188939

Keyword

nonn,more

Author

N. J. A. Sloane, Apr 14 2011

Extensions

a(22)-a(30) from Joerg Arndt, Apr 25 2011

a(31)-a(33) from Vincenzo Librandi, May 13 2011

a(36) from Charles R Greathouse IV, Oct 10 2011

a(37)-a(39) from Charles R Greathouse IV, Oct 11 2011

a(34)-a(35) inserted by Michael S. Branicky, Jul 25 2024

Status

approved