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 A030740 #4 Mar 30 2012 18:56:19 %S A030740 2,1,5,6,8,12,11,17,16,24,58,23,33,218,32,44,161,43,57,158,56,72,157, %T A030740 71,90,156,319,89,180,210,109,242,155,131,278,154,277,178,406,315,405, %U A030740 241,358,276,208,681,314,240,452,620,356,275 %N A030740 a(n)=least k such that s(k)=n, where s=A030737. %K A030740 nonn %O A030740 2,1 %A A030740 _Clark Kimberling_