cp's OEIS Frontend

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.

A256701 Positive part of the minimal alternating binary representation of n (defined at A245596).

Original entry on oeis.org

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, 34, 36, 32, 33, 32, 32, 32, 65, 66, 68, 68, 73, 72, 72, 72, 81, 82, 84, 80, 81, 80, 80, 64, 65, 66, 68, 68, 73, 72, 72, 64, 65, 66, 68, 64, 65, 64, 64, 64, 129, 130
Offset: 1

Views

Author

Clark Kimberling, Apr 09 2015

Keywords

Examples

			R(1) = 1; positive part 1, nonpositive part 0
R(2) = 2; positive part 2, nonpositive part 0
R(3) = 4 - 1; positive part 4, nonpositive part 1
R(11) = 16 - 8 + 4 - 1; positive part 16+4 = 20; nonpositive part 8 + 1 = 9
		

Crossrefs

Programs

  • Mathematica
    b[n_] := 2^n; bb = Table[b[n], {n, 0, 40}];
    s[n_] := Table[b[n + 1], {k, 1, b[n]}];
    h[0] = {1}; h[n_] := Join[h[n - 1], s[n - 1]];
    g = h[10]; Take[g, 100]; r[0] = {0};
    r[n_] := If[MemberQ[bb, n], {n}, Join[{g[[n]]}, -r[g[[n]] - n]]]
    Table[Total[Abs[r[n]]], {n, 1, 100}] (* A073122 *)
    u = Table[Total[(Abs[r[n]] + r[n])/2], {n, 1, 100}]  (* A256701 *)
    v = Table[Total[(Abs[r[n]] - r[n])/2], {n, 1, 100}]  (* A256702 *)

Formula

A256701(n) - A256702(n) = n.