A309726 - OEIS

%I #22 Jan 15 2023 02:08:12

%S 5,7,11,13,17,19,25,29,35,41,49,53,59,61,79,85,91,95,97,103,107,113,

%T 119,121,137,139,145,149,163,169,173,179,181,185,191,205,209,227,233,

%U 235,245,251

%N Numbers k such that k^2 - 12 is prime.

%C All terms are odd and not divisible by 3.

%H Harvey P. Dale, <a href="/A309726/b309726.txt">Table of n, a(n) for n = 1..1000</a>

%F If A056927(k) = 12, then k is a term. - _A.H.M. Smeets_, Aug 15 2019

%e 11 is in the sequence because 11^2 - 12 = 109, which is prime.

%t Select[Range[5,301,2],PrimeQ[#^2-12]&] (* _Harvey P. Dale_, Dec 23 2019 *)

%o (PARI) select(n->isprime(n^2-12), [1..1000]) \\ _Andrew Howroyd_, Aug 14 2019

%Y Cf. A028870, A028873, A028876, A028879, A028882, A028885, A186815, A090696, A296507.

%Y Cf. A056927.

%K nonn

%O 1,1

%A _Daniel Starodubtsev_, Aug 14 2019