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 A030602 #4 Mar 30 2012 18:56:19 %S A030602 1,1,1,2,3,4,4,5,5,4,5,4,4,3,3,3,4,4,4,4,4,4,5,5,5,5,5,5,6,6,6,6,6,7, %T A030602 7,8,9,9,9,10,10,10,11,12,13,14,15,15,16,17,17,18,17,18,19,18,18,19, %U A030602 18,18,19,19,20,21,21,21,22,22,22,23,23,24,25 %N A030602 a(n)=(# 1's)-(# 2's) in first n terms of A030588. %K A030602 nonn %O A030602 1,4 %A A030602 _Clark Kimberling_