OFFSET
1,1
LINKS
Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1.
Yash Puri and Thomas Ward, A dynamical property unique to the Lucas sequence, Fibonacci Quarterly, Volume 39, Number 5 (November 2001), pp. 398-402.
FORMULA
a(n) = (1/n)* Sum_{d|n} mu(d)*A000051(n/d).
EXAMPLE
a(3)=2 since the 3rd term of A000051 is 9 and the first term is 3.
PROG
(PARI) a000051(n) = 2^n+1;
a(n) = (1/n)*sumdiv(n, d, moebius(d)*a000051(n/d)); \\ Michel Marcus, Sep 11 2017
(Python)
from sympy import mobius, divisors
def A060477(n): return sum(mobius(n//d)*(2**d+1) for d in divisors(n, generator=True))//n # Chai Wah Wu, Feb 03 2022
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
STATUS
approved