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
Links
- Daniel Shanks, Gauss's ternary form reduction and the 2-Sylow subgroup, Math. Comp. 25 (1971), 837-853.
Programs
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PARI
for(n=1,10^6,if(isprime((2^n+3)^2-8),print1(n,", "))); /* Joerg Arndt, Apr 25 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