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 A272686 #10 May 25 2016 01:40:44 %S A272686 0,3,10,36,134,510,1976,7770,30934,124456,505254,2067250,8516028, %T A272686 35292978,147045490,615572172,2587970166,10922249958,46257477232, %U A272686 196532215226,837432161710,3577882539792,15323984114822,65781749593002,282979540332660 %N A272686 Second differences of A078482. %Y A272686 Cf. A078482, A272687. %K A272686 nonn %O A272686 0,2 %A A272686 _N. J. A. Sloane_, May 24 2016