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 A015039 #4 Mar 30 2012 17:20:37
%S A015039 1,1,65,266817,69963653697,1173835620696269377,
%T A015039 1260401809332973746871411265,86614199277767115453624156235708310081,
%U A015039 380933302489206359659857650468008737411766944866881
%N A015039 q-Catalan numbers (binomial version) for q=8.
%F A015039 {1 / (n+1)_q} {2 n choose n}_q.
%K A015039 nonn,easy
%O A015039 0,3
%A A015039 _Olivier Gérard_