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 A250220 #15 Apr 02 2020 04:36:22 %S A250220 7,9,12,16,17,18,26,34,36,38,39,42,49,74,114,118,337,396,455 %N A250220 Numbers k such that A241601(k) is prime. %C A250220 Is the sequence infinite? %C A250220 No other terms < 500. - _Jinyuan Wang_, Apr 02 2020 %Y A250220 Cf. A241601, A249909, A246006, A112548, A092132, A103234. %K A250220 nonn,more %O A250220 1,1 %A A250220 _Eric Chen_, Dec 24 2014 %E A250220 a(17)-a(19) from _Jinyuan Wang_, Apr 02 2020