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 A059131 #5 May 20 2014 14:52:31
%S A059131 1,2,1,2,3,2,1,2,1,2,3,2,3,4,3,2,3,2,1,2,1,2,3,2,1,2,1,3,4,3,4,5,4,3,
%T A059131 4,3,1,2,1,2,3,2,1,2,1,2,3,2,3,4,3,2,3,2,1,2,1,2,3,2,1,2,1,4,5,4,5,6,
%U A059131 5,4,5,4,1,2,1,2,3,2,1,2,1,2,3,2,3,4,3,2,3,2,1,2,1,2,3,2,1,2,1,3,4,3,4,5,4
%N A059131 A hierarchical sequence (W3{2,2}* - see A059126).
%H A059131 J. Wallgren, <a href="/A059126/a059126.txt">Hierarchical sequences</a>
%K A059131 easy,nonn
%O A059131 0,2
%A A059131 _Jonas Wallgren_, Jan 19 2001