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 A030550 #4 Mar 30 2012 18:56:18 %S A030550 1,6,8,9,10,12,14,16,21,33,45,57,66,69,71,72,75,78,81,84,85,87,88,89, %T A030550 90,91,93,94,96,97,99,100,102,105,107,108,111,114,117,120,123,125,126, %U A030550 129,132,135,138,141,143,144,147,150,153,156,159 %N A030550 Position of n-th 1 in A030548. %K A030550 nonn %O A030550 1,2 %A A030550 _Clark Kimberling_