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 A084507 #16 Feb 21 2025 15:32:47 %S A084507 63,17,5,1,4,18,96,510,2580,12522,58920,270870,1223292 %N A084507 First occurrence of n in A084501. %H A084507 Antti Karttunen, <a href="/A084507/a084507.scm.txt">Scheme-program for computing this sequence</a> %Y A084507 Cf. A084501, A084517, A084527. %K A084507 nonn,more %O A084507 0,1 %A A084507 _Antti Karttunen_, Jun 02 2003