This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A303739 #9 Jul 21 2021 00:43:51 %S A303739 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 A303739 56,63,64,77,82,93,96,103,112,114,116,117,119,123,126,127,134,135,138, %U A303739 142,145,149,151,152,163,165,175,177,179,180,189,193,194,201,203 %N A303739 Numbers k such that 9*k^2 + 3*k + 1 (A082040) is prime. %C A303739 These are the indices of the primes in A082040. %p A303739 select(n->isprime(9*n^2+3*n+1),[$0..300]); %o A303739 (GAP) Filtered([0..300],n->IsPrime(9*n^2+3*n+1)); %Y A303739 Cf. A082040, A303740 (corresponding primes). %K A303739 nonn %O A303739 1,2 %A A303739 _Muniru A Asiru_, Jun 01 2018