OFFSET
0,2
LINKS
PROG
(Python)
from sympy import mobius, prime, log
import math
def A(n): return n - 2**int(math.floor(log(n, 2)))
def b(n): return n + 1 if n<2 else prime(1 + (len(bin(n)[2:]) - bin(n)[2:].count("1"))) * b(A(n))
def a(n): return mobius(b(n))%3 # Indranil Ghosh, May 30 2017
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, May 30 2017
STATUS
approved