%I #12 Feb 25 2023 06:46:24

%S 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,

%T 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,

%U 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

%N a(n) = A007302(n) - 1.

%H Vincenzo Librandi, <a href="/A280737/b280737.txt">Table of n, a(n) for n = 1..10000</a>

%H Alma D'Aniello, Aldo de Luca, and Alessandro De Luca, <a href="http://arxiv.org/abs/1602.03231">On Christoffel and standard words and their derivatives</a>, arXiv:1602.03231 [cs.DM], 2016 (mentions this sequence).

%o (PARI) a(n)=hammingweight(bitxor(n,3*n))-1; \\ _Joerg Arndt_, Feb 25 2023

%Y Cf. A007302.

%K nonn

%O 1,11

%A _N. J. A. Sloane_, Jan 11 2017