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 A189726 #6 Mar 30 2012 18:57:25 %S A189726 0,1,2,3,3,4,5,5,6,7,7,8,8,9,10,11,11,12,13,13,14,14,15,16,17,17,18, %T A189726 19,19,20,20,21,22,23,23,24,24,25,26,27,27,28,29,29,30,31,31,32,32,33, %U A189726 34,35,35,36,37,37,38,38,39,40,41,41,42,42,43,44,45,45,46,47,47,48,49,49,50,50,51,52,53,53,54 %N A189726 Partial sums of A189723. %C A189726 See A189723. %F A189726 s(n)=s([(n+2)/3])+[(n+1)/3]-s([(n+1)/3])+[n/3], where s(0)=0, s(1)=0. %t A189726 (See A189723.) %Y A189726 Cf. A189723, A189724, A189725. %K A189726 nonn %O A189726 1,3 %A A189726 _Clark Kimberling_, Apr 26 2011