OFFSET
0,1
FORMULA
a(n) = Sum_{d|n} q(d), where q(x) = A002110(x).
EXAMPLE
n=6: divisors = {1,2,3,6}; 2 + 2*3 + 2*3*5 + 2*3*5*7*11*13 = 2 + 6 + 30 + 30030 = 30068.
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jul 19 2001
STATUS
approved