OFFSET
1,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
FORMULA
G.f.: Sum_{k>=1} mu(k) * x^k / (1 - 2*x^k - x^(2*k)). - Ilya Gutkovskiy, Feb 06 2020
EXAMPLE
a(4) = 10 = (0, -1, 0, 1) dot (1, 2, 5, 12) = (0, -2, 0, 12).
MAPLE
with(numtheory):
a:= n-> add(mobius(n/d)*(<<0|1>, <1|2>>^d. <<0, 1>>)[1, 1], d=divisors(n)):
seq(a(n), n=1..40); # Alois P. Heinz, Sep 26 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Gary W. Adamson, Sep 21 2007
STATUS
approved