A286576 - OEIS

%I #8 Jun 01 2017 13:51:51

%S 1,2,2,0,2,1,0,0,2,1,1,0,0,0,0,0,2,1,1,0,1,2,0,0,0,0,0,0,0,0,0,0,2,1,

%T 1,0,1,2,0,0,1,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,1,1,0,

%U 1,2,0,0,1,2,2,0,0,0,0,0,1,2,2,0,2,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0

%N a(n) = A132971(n) mod 3.

%H Antti Karttunen, <a href="/A286576/b286576.txt">Table of n, a(n) for n = 0..10922</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%F a(n) = A010872(A132971(n)) = A132971(n) mod 3.

%o (Scheme) (define (A286576 n) (modulo (A132971 n) 3))

%o (Python)

%o from sympy import mobius, prime, log

%o import math

%o def A(n): return n - 2**int(math.floor(log(n, 2)))

%o def b(n): return n + 1 if n<2 else prime(1 + (len(bin(n)[2:]) - bin(n)[2:].count("1"))) * b(A(n))

%o def a(n): return mobius(b(n))%3 # _Indranil Ghosh_, May 30 2017

%Y Cf. A010872, A132971.

%K nonn,base

%O 0,2

%A _Antti Karttunen_, May 30 2017