OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
FORMULA
a(n) = (1/n) * Sum_{k=1..n} a(n-k)*b(k), k>0, a(0)=1, b(k)=Sum_{d|k} (-1)^(k/d+1)*d*prime(d).
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Apr 16 2001
STATUS
approved