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 A078569 #6 Dec 15 2017 17:36:09 %S A078569 1,5,25,53,370 %N A078569 Numbers n such that A078568(n) is prime. %C A078569 Some of the larger entries may only correspond to probable primes. %Y A078569 Cf. A002275, A000422, A078568. %K A078569 more,nonn %O A078569 1,2 %A A078569 _Jason Earls_, Nov 29 2002