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 A030743 #4 Mar 30 2012 18:56:19 %S A030743 2,3,9,10,15,21,22,30,31,41,42,54,55,69,70,81,87,88,107,108,129,130, %T A030743 153,177,193,196,199,202,205,207,234,239,253,268,274,305,310,312,346, %U A030743 348,351,354,381,397,400,441,446,449,488,490,500 %N A030743 s(k)=1, where s=A030737. %K A030743 nonn %O A030743 1,1 %A A030743 _Clark Kimberling_