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 A031268 #4 Mar 30 2012 18:56:21 %S A031268 0,1,1,1,1,1,1,0,0,0,0,1,2,2,3,3,4,3,2,2,1,2,2,2,2,2,2,2,2,2,1,1,1,1, %T A031268 1,1,2,2,2,2,2,2,2,2,2,1,1,2,2,2,3,4,4,3,3,3,2,2,2,1,0,0,0,0,0,0,1,1, %U A031268 1,1,1,1,1,1,1,0,0,0,0,0,0,1,1,2,2,2,3,3,3,4 %N A031268 a(n)=(# 3's)-(# 4's) in first n terms of A031253. %K A031268 nonn %O A031268 1,13 %A A031268 _Clark Kimberling_