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 A030384 #4 Mar 30 2012 18:56:18 %S A030384 1,0,0,1,1,2,3,4,3,4,4,3,3,2,3,2,1,0,0,0,0,0,1,1,0,0,0,1,1,1,2,2,3,4, %T A030384 4,3,4,4,4,5,6,6,7,8,9,10,11,10,11,12,12,13,12,12,13,12,13,14,13,12, %U A030384 13,12,12,13,13,13,14,14,15,16,16,15,16,16,16 %N A030384 a(n)=(# 1's)-(# 2's) in first n terms of s=A030373. %K A030384 nonn %O A030384 1,6 %A A030384 _Clark Kimberling_