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 A309421 #11 Aug 04 2019 04:41:33 %S A309421 24,1036,104824 %N A309421 Numbers k such that 5^k + k^5 is prime. %C A309421 a(4) > 125000. %Y A309421 Cf. A001593, A114973, A309422. %K A309421 nonn,bref,more,hard %O A309421 1,1 %A A309421 _Hugo Pfoertner_, Jul 30 2019