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 A044516 #5 Mar 30 2012 18:56:45 %S A044516 33,69,105,141,177,203,213,249,285,321,357,393,419,429,465,501,537, %T A044516 573,609,635,645,681,717,753,789,825,851,861,897,933,969,1005,1041, %U A044516 1067,1077,1113,1149,1185,1223,1257,1283,1293,1329 %N A044516 Numbers n such that string 5,3 occurs in the base 6 representation of n but not of n+1. %K A044516 nonn,base %O A044516 1,1 %A A044516 _Clark Kimberling_