OFFSET
1,2
COMMENTS
A sequence in Table 1 of Hao (1991) appears to match this sequence, but there are not enough terms there to be certain. It is possible that Hao's 1989 book will clarify things, but I do not have access to it.
REFERENCES
Hao, Bai Lin, Elementary symbolic dynamics and chaos in dissipative systems. World Scientific Publishing Co., Inc., Teaneck, NJ, 1989. xvi+460 pp. ISBN: 9971-50-682-3; 9971-50-698-X
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..200
Bai-lin Hao, Symbolic dynamics and characterization of complexity, Physica, D51 (1991), 161-176.
FORMULA
a(n) = (1/8*n) * Sum_{d|n, d odd} mu(d)*(3^(2*n/d) - 1). - Andrew Howroyd, Nov 11 2018
MATHEMATICA
a[n_] := Sum[Boole[OddQ[d]] MoebiusMu[d] (3^(2n/d)-1), {d, Divisors[n]}]/(8n);
Array[a, 22] (* Jean-François Alcover, Aug 26 2019 *)
PROG
(PARI) a(n) = sumdiv(n>>valuation(n, 2), d, moebius(d)*(3^(2*n/d)-1))/(8*n); \\ Andrew Howroyd, Nov 11 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 01 2015
EXTENSIONS
Offset corrected and terms a(14) and beyond from Andrew Howroyd, Nov 11 2018
STATUS
approved