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 A202952 #12 Apr 10 2017 00:06:07 %S A202952 0,0,0,0,2,11,0,0,2300 %N A202952 A108235(n)-A202951(n). %H A202952 R. J. Nowakowski, <a href="/A104429/a104429.pdf">Generalizations of the Langford-Skolem problem</a>, M.S. Thesis, Dept. Math., Univ. Calgary, May 1975. [Scanned copy, with permission.] %Y A202952 Cf. A108235, A202951. %K A202952 nonn,more %O A202952 0,5 %A A202952 _N. J. A. Sloane_, Dec 26 2011