OFFSET
1,4
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
a(n) = numerator of f(n), where f(1) = 1, f(n) = (1/2) * (A173557(n) - Sum_{d|n, d>1, d<n} f(d) * f(n/d)) for n > 1.
PROG
CROSSREFS
KEYWORD
sign,frac
AUTHOR
Antti Karttunen, Aug 24 2018
STATUS
approved