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 A030563 #4 Mar 30 2012 18:56:18 %S A030563 1,0,0,0,0,1,1,2,3,4,3,4,4,5,5,6,6,5,5,4,5,4,3,2,2,1,1,0,0,0,0,0,1,1, %T A030563 0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,1,1,1, %U A030563 2,2,3,4,4,3,4,4,4,5,5,5,6,6,6,7,8,8,9,10,11 %N A030563 a(n)=(# 1's)-(# 2's) in first n terms of A030548. %K A030563 nonn %O A030563 1,8 %A A030563 _Clark Kimberling_