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.

A268273 Negabinary odious numbers (see comment).

Original entry on oeis.org

1, 3, 4, 6, 9, 11, 12, 15, 16, 18, 21, 23, 24, 26, 29, 30, 33, 35, 36, 38, 41, 43, 44, 47, 48, 50, 53, 54, 57, 59, 60, 63, 64, 66, 69, 71, 72, 74, 77, 78, 81, 83, 84, 86, 89, 91, 92, 95, 96, 98, 101, 103, 104, 106, 109, 110, 113, 115, 116, 119, 120, 122, 125
Offset: 1

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Author

Vladimir Shevelev, Mar 02 2016

Keywords

Comments

Recall that a number n>=1 is defined as odious number (A000069) if its binary expansion contains an odd number of 1's, or such n that Thue-Morse sequence A010060(n)=1. Sequence A269027 is essentially Thue-Morse sequence in "negabinary", i.e., in base -2. So a number n for which A269027(n)=1 it is natural to call "negabinary odious".

Crossrefs

Programs

  • Mathematica
    b = 2; Select[Range[0, 125], Function[k, OddQ@ Total@ Rest@ Reverse@ Mod[NestWhileList[(# - Mod[#, b])/-b &, k, # != 0 &], b]]] (* Michael De Vlieger, Mar 03 2016, after Robert Lozyniak at A039724 *)

Extensions

More terms from Peter J. C. Moses, Mar 02 2016