OFFSET
1,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = Sum_{d|n} A001405(n/d)*mu(d).
EXAMPLE
n=7, C[7,3]=35, A001405[7/d]={C[7,3],C[1,0]}={35,1}, mu[d]={1,-1}, the sum is a(7)=35-1=34.
MAPLE
with(numtheory):
a:= n-> add(binomial(d, iquo(d, 2))*mobius(n/d), d=divisors(n)):
seq(a(n), n=1..40); # Alois P. Heinz, Jul 09 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jul 19 2001
EXTENSIONS
Offset corrected by Eric Rowland, Jul 09 2017
STATUS
approved