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 A038661 #4 May 19 2013 12:18:42 %S A038661 217,61,124,331,56,1261,19,271,866,387,26,7,21931,17498,316,469,152, %T A038661 6795,37,169,448,1330,63488,3880,127,631,604,63,2015,1951,55393,2648, %U A038661 784,513,2072,2196,665,10267,5489,85696,48728,10523,2863,342,1216,4401 %N A038661 First gap of n in sequence A038593 (lower terms). %K A038661 nonn %O A038661 1,1 %A A038661 _Jeff Burch_