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 A308413 #29 Aug 16 2019 15:21:41
%S A308413 6,60,66,414,29340
%N A308413 Numbers k such that 23^(k+19) + 19^(k+17) + 17^(k+13) + 13^(k+11) + 11^(k+7) + 7^(k+5) + 5^(k+3) + 3^(k+2) - 1 is prime.
%C A308413 a(6) > 50000 (if it exists).
%t A308413 ParallelTable[If[PrimeQ[23^(n+19) + 19^(n+17) + 17^(n+13) + 13^(n+11) + 11^(n+7) + 7^(n+5) + 5^(n+3) + 3^(n+2) - 1], n, Nothing], {n, 30000}]
%Y A308413 Cf. A306573.
%K A308413 nonn,hard,more,less
%O A308413 1,1
%A A308413 _Mikk Heidemaa_, May 31 2019