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 A030565 #4 Mar 30 2012 18:56:18 %S A030565 0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,1,1,2,2,3, %T A030565 3,4,5,6,5,6,6,5,5,4,4,3,3,2,3,2,1,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0, %U A030565 0,0,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0 %N A030565 (# 3's)-(# 4's) in first n terms of A030548. %K A030565 nonn %O A030565 1,32 %A A030565 _Clark Kimberling_