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 A015041 #4 Mar 30 2012 17:20:37
%S A015041 1,1,101,1011101,1011212121101,101122324343423221101,
%T A015041 1011224355769798979675534221101,
%U A015041 1011224467004378104253524007733996644221101
%N A015041 q-Catalan numbers (binomial version) for q=10.
%F A015041 {1 / (n+1)_q} {2 n choose n}_q.
%K A015041 nonn,easy
%O A015041 0,3
%A A015041 _Olivier Gérard_