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.

A129761 First differences of Fibbinary numbers (A003714).

Original entry on oeis.org

1, 1, 2, 1, 3, 1, 1, 6, 1, 1, 2, 1, 11, 1, 1, 2, 1, 3, 1, 1, 22, 1, 1, 2, 1, 3, 1, 1, 6, 1, 1, 2, 1, 43, 1, 1, 2, 1, 3, 1, 1, 6, 1, 1, 2, 1, 11, 1, 1, 2, 1, 3, 1, 1, 86, 1, 1, 2, 1, 3, 1, 1, 6, 1, 1, 2, 1, 11, 1, 1, 2, 1, 3, 1, 1, 22, 1, 1, 2, 1, 3, 1, 1, 6, 1, 1, 2, 1, 171, 1, 1, 2, 1, 3, 1, 1, 6
Offset: 0

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Author

Ralf Stephan, May 14 2007

Keywords

Comments

Theorem: If the Zeckendorf representation of M ends with exactly k >= 0 zeros, ...10^k, then a(n) = ceiling(2^k/3). Also, if the Zeckendorf representation of n (A014417(n)) is even then a(n) is given by A319952, otherwise a(n) = 1. - Jeffrey Shallit and N. J. A. Sloane, Oct 03 2018

Crossrefs

Programs

  • Maple
    with(combinat): F:=fibonacci:
    A072649:= proc(n) local j; global F; for j from ilog[(1+sqrt(5))/2](n)
           while F(j+1)<=n do od; (j-1); end:
    A003714 := proc(n) global F; option remember; if(n < 3) then RETURN(n); else RETURN((2^(A072649(n)-1))+A003714(n-F(1+A072649(n)))); fi; end:
    A129761 := n -> A003714(n+1)-A003714(n):
    [seq(A129761(n),n=0..120)]; # N. J. A. Sloane, Oct 03 2018, borrowing programs from other sequences
  • Mathematica
    Differences[Select[Range[600], !MemberQ[Partition[IntegerDigits[#, 2], 2, 1], {1, 1}] &]] (* Harvey P. Dale, Jul 17 2011 *)

Formula

a(n) = A005578(A035614(n)). - Alan Michael Gómez Calderón, Nov 01 2023

Extensions

a(0)=1 added by N. J. A. Sloane, Oct 02 2018