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 A189671 #8 Apr 24 2019 15:14:19
%S A189671 0,1,1,2,2,2,2,3,3,4,4,4,4,5,5,5,6,6,6,7,7,8,8,8,8,9,9,10,10,10,10,11,
%T A189671 11,11,12,12,12,13,13,14,14,14,14,15,15,15,16,16,17,17,17,17,18,18,18,
%U A189671 19,19,20,20,20,20,21,21,22,22,22,22,23,23,23,24,24,24,25,25,26,26,26,26,27,27,28
%N A189671 Partial sums of A189668.
%C A189671 See A189668.
%F A189671 s(n)=s([(n+2)/3])+[(n+1)/3]-s([(n+1)/3]), where s(0)=0, s(1)=0.
%t A189671 (See A189668.)
%t A189671 Accumulate[Nest[Flatten[#/.{0->{0,1,0},1->{1,0,0}}]&,{0},5]] (* _Harvey P. Dale_, Apr 24 2019 *)
%Y A189671 Cf. A189668, A189669, A189670.
%K A189671 nonn
%O A189671 1,4
%A A189671 _Clark Kimberling_, Apr 25 2011