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 A370661 #7 Feb 29 2024 01:38:56 %S A370661 1,3,7,15,3907 %N A370661 Numbers k such that (8^k + 8*k)/8 is prime. %C A370661 If it exists, a(6) > 50000. %o A370661 (PARI) is(n) = ispseudoprime(8^(n-1) + n) %Y A370661 Cf. A221910, A226201. %K A370661 nonn,hard,more %O A370661 1,2 %A A370661 _Hugo Pfoertner_, Feb 27 2024