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 A256701 #4 Apr 13 2015 09:40:21 %S A256701 1,2,4,4,9,8,8,8,17,18,20,16,17,16,16,16,33,34,36,36,41,40,40,32,33, %T A256701 34,36,32,33,32,32,32,65,66,68,68,73,72,72,72,81,82,84,80,81,80,80,64, %U A256701 65,66,68,68,73,72,72,64,65,66,68,64,65,64,64,64,129,130 %N A256701 Positive part of the minimal alternating binary representation of n (defined at A245596). %H A256701 Clark Kimberling, <a href="/A256701/b256701.txt">Table of n, a(n) for n = 1..1000</a> %F A256701 A256701(n) - A256702(n) = n. %e A256701 R(1) = 1; positive part 1, nonpositive part 0 %e A256701 R(2) = 2; positive part 2, nonpositive part 0 %e A256701 R(3) = 4 - 1; positive part 4, nonpositive part 1 %e A256701 R(11) = 16 - 8 + 4 - 1; positive part 16+4 = 20; nonpositive part 8 + 1 = 9 %t A256701 b[n_] := 2^n; bb = Table[b[n], {n, 0, 40}]; %t A256701 s[n_] := Table[b[n + 1], {k, 1, b[n]}]; %t A256701 h[0] = {1}; h[n_] := Join[h[n - 1], s[n - 1]]; %t A256701 g = h[10]; Take[g, 100]; r[0] = {0}; %t A256701 r[n_] := If[MemberQ[bb, n], {n}, Join[{g[[n]]}, -r[g[[n]] - n]]] %t A256701 Table[Total[Abs[r[n]]], {n, 1, 100}] (* A073122 *) %t A256701 u = Table[Total[(Abs[r[n]] + r[n])/2], {n, 1, 100}] (* A256701 *) %t A256701 v = Table[Total[(Abs[r[n]] - r[n])/2], {n, 1, 100}] (* A256702 *) %Y A256701 Cf. A245596, A073122, A256702. %K A256701 nonn,easy %O A256701 1,2 %A A256701 _Clark Kimberling_, Apr 09 2015