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 A083057 #7 Mar 30 2012 18:39:18 %S A083057 2,3,3,2,0,0,-1,0,0,-1,0,0,2,3,6,8,9,12,14,18,21,23,24,24,26,27,30,32, %T A083057 33,33,32,33,33,35,36,36,38,39,42,44,45,45,44,45,45,47,48,48,47,45,45, %U A083057 44,45,45,44,42,39,38,36,36,35,33,33,32,33,33,32,30,27,26,24,24,23,21,18,14,12,9,8,6,3,2,0,0,-1,0,0,-1,0,0,2,3,3,2,0 %N A083057 A fractal sequence. %H A083057 Boris Gourevitch, <a href="http://membres.lycos.fr/bgourevitch/temporaires/benoit/sqrt3fractal.jpg">Graph of A083057</a> %F A083057 a(n)=sum(k=1, n, A083056(k)) %Y A083057 Cf. A083038, A083054, A083055, A083056. %K A083057 sign %O A083057 1,1 %A A083057 _Benoit Cloitre_, Apr 18 2003