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 A281048 #18 Feb 27 2017 21:19:53
%S A281048 1,0,-1,1,-2,1,1,0,-3,1,2,-1,1,0,-1,1,-4,1,3,-2,3,-1,-2,1,1,0,-1,1,-2,
%T A281048 1,1,0,-5,1,4,-3,5,-2,-3,1,4,-1,-3,2,-3,1,2,-1,1,0,-1,1,-2,1,1,0,-3,1,
%U A281048 2,-1,1,0,-1,1,-6,1,5,-4,7,-3,-4,1,7,-2,-5,3,-4,1,3,-2,5,-1,-4,3,-5,2,3,-1,-4,1,3,-2,3,-1,-2,1,1,0,-1,1
%N A281048 Expansion of x*(1 - x)*Product_{k>=0} (1 + x^(2^k) - x^(2^(k+1))).
%C A281048 First differences of A005590.
%H A281048 Michael Gilleland, <a href="/selfsimilar.html">Some Self-Similar Integer Sequences</a>
%H A281048 Ilya Gutkovskiy, <a href="/A281048/a281048.pdf">Extended graphical example</a>
%H A281048 R. Stephan, <a href="http://arXiv.org/abs/math.CO/0307027">Divide-and-conquer generating functions. I. Elementary sequences</a>, arXiv:math/0307027 [math.CO], 2003.
%F A281048 G.f.: x*(1 - x)*Product_{k>=0} (1 + x^(2^k) - x^(2^(k+1))).
%t A281048 Rest[CoefficientList[Series[x (1 - x) Product[1 + x^2^k - x^2^(k + 1), {k, 0, 15}], {x, 0, 100}], x]]
%t A281048 Differences[a[0] = 0; a[1] = 1; a[n_] := a[n] = If[OddQ[n], a[(n-1)/2 + 1] - a[(n-1)/2], a[n/2]]; Table[a[n], {n, 0, 100}]]
%Y A281048 Cf. A005590, A070990, A182093.
%K A281048 sign
%O A281048 1,5
%A A281048 _Ilya Gutkovskiy_, Feb 27 2017