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 A261926 #3 Sep 17 2015 19:37:41 %S A261926 3,3,3,6,3,3,6,9,5,6,5,7,9,5,6,3,3,6,9,5,7,5,9,3,5,3,6,3,3,6,10,6,7,7, %T A261926 9,5,5,5,7,7,5,5,9,9,9,5,6,3,3,6,9,5,6,5,7,10,6,7,3,6,9,7,7,9 %N A261926 First differences of A261416. %Y A261926 Cf. A261416, A260273. %K A261926 nonn %O A261926 1,1 %A A261926 _N. J. A. Sloane_, Sep 17 2015