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 A044877 #5 Mar 30 2012 18:56:47 %S A044877 217,218,219,220,221,223,230,237,244,251,253,254,255,256,257,264,265, %T A044877 267,268,269,270,271,272,274,275,276,277,278,279,281,282,283,284,285, %U A044877 286,288,295,300,301,303,304,305,309,316,323 %N A044877 Numbers having, in base 6, (sum of even run lengths)=(sum of odd run lengths). %K A044877 nonn,base %O A044877 1,1 %A A044877 _Clark Kimberling_