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 A030397 #4 Mar 30 2012 18:56:18 %S A030397 1,0,0,0,1,2,3,2,3,3,4,4,3,4,3,2,1,1,0,0,0,1,1,0,0,0,0,0,0,1,2,2,3,2, %T A030397 2,3,3,3,4,4,5,6,7,8,9,8,9,10,10,11,12,12,11,12,13,12,13,12,11,12,12, %U A030397 11,12,12,12,13,14,14,15,14,14,15,15,15,16,16 %N A030397 a(n)=(# 1's)-(# 2's) in first n terms of A030386. %K A030397 nonn %O A030397 1,6 %A A030397 _Clark Kimberling_