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 A038031 #3 Mar 30 2012 17:37:06 %S A038031 2,19,19,43,103,43,137,149,103,83,71,233,137,149,373,389,479,1021,233, %T A038031 647,691,487,197,419,2459,619,389,1543,1021,647,691,4349,1019,419, %U A038031 4817,6581,3067,2939,6983,2389,8783,1489,2549,2459,2887,11621 %N A038031 Position reached by frog in A038029. A038026(A038029(n)). %Y A038031 Cf. A038025. %K A038031 nonn %O A038031 1,1 %A A038031 _Christian G. Bower_