A280737 a(n) = A007302(n) - 1.

0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 2, 1, 2, 1, 1, 0, 1, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 1, 1, 0, 1, 1, 2, 1, 2, 2, 2, 1, 2, 2, 3, 2, 3, 2, 2, 1, 2, 2, 3, 2, 3, 2, 2, 1, 2, 2, 2, 1, 2, 1, 1, 0, 1, 1, 2, 1, 2, 2, 2, 1, 2, 2, 3, 2, 3, 2, 2, 1, 2, 2, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 3, 2, 2, 1, 2, 2, 3

Offset: 1

Author

N. J. A. Sloane, Jan 11 2017

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..10000
• Alma D'Aniello, Aldo de Luca, and Alessandro De Luca, On Christoffel and standard words and their derivatives, arXiv:1602.03231 [cs.DM], 2016 (mentions this sequence).

Crossrefs

Cf. A007302.

Programs

PARI

a(n)=hammingweight(bitxor(n,3*n))-1; \\ Joerg Arndt, Feb 25 2023