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 A044875 #5 Mar 30 2012 18:56:47 %S A044875 65,66,67,69,74,79,81,82,83,88,89,91,92,93,94,96,101,104,105,107,111, %T A044875 112,117,122,124,125,126,129,130,131,133,138,143,144,148,150,151,154, %U A044875 159,161,162,163,164,166,167,172,173,174,176 %N A044875 Numbers having, in base 4, (sum of even run lengths)=(sum of odd run lengths). %K A044875 nonn,base %O A044875 1,1 %A A044875 _Clark Kimberling_