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 A015072 #4 Mar 30 2012 17:20:37
%S A015072 1,1,65,265793,69690957377,1169189032203853377,
%T A015072 1255411354557002675473292865,86271175378590615960023796743819697729,
%U A015072 379424661671199524960693236715772257964919647837761
%N A015072 q-Catalan numbers (binomial version) for q=-8.
%F A015072 {1 / (n+1)_q} {2 n choose n}_q.
%K A015072 nonn,easy
%O A015072 0,3
%A A015072 _Olivier Gérard_