OFFSET
0,2
COMMENTS
tau(n) = A000005(n) = the number of divisors of n.
PROG
(PARI) {a(n)=polcoeff(exp(sum(m=1, n, x^m/m*sumdiv(m, d, d*2^(m/d)*sigma(d, 0)))+x*O(x^n)), n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Apr 04 2010
STATUS
approved