A303739 - OEIS

%I #9 Jul 21 2021 00:43:51

%S 1,2,4,5,7,8,9,11,18,19,22,23,25,26,30,33,35,37,39,46,47,49,50,51,54,

%T 56,63,64,77,82,93,96,103,112,114,116,117,119,123,126,127,134,135,138,

%U 142,145,149,151,152,163,165,175,177,179,180,189,193,194,201,203

%N Numbers k such that 9*k^2 + 3*k + 1 (A082040) is prime.

%C These are the indices of the primes in A082040.

%p select(n->isprime(9*n^2+3*n+1),[$0..300]);

%o (GAP) Filtered([0..300],n->IsPrime(9*n^2+3*n+1));

%Y Cf. A082040, A303740 (corresponding primes).

%K nonn

%O 1,2

%A _Muniru A Asiru_, Jun 01 2018