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 A030398 #4 Mar 30 2012 18:56:18 %S A030398 0,1,0,0,0,0,0,1,1,0,0,0,1,1,2,3,4,3,4,4,3,3,2,3,2,1,0,0,0,0,0,0,0,1, %T A030398 1,1,0,0,0,0,0,0,0,0,0,1,1,1,0,0,0,0,1,1,1,2,2,3,4,4,3,4,4,4,3,3,3,2, %U A030398 2,3,2,2,1,0,0,0,0,1,1,1,2,3,3,4,3,3,4,4,4,5 %N A030398 a(n)=(# 2's)-(# 3's) in first n terms of A030386. %K A030398 nonn %O A030398 1,15 %A A030398 _Clark Kimberling_