OFFSET
1,2
COMMENTS
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
FORMULA
G.f.: Sum_{n>=1} n*x^n/(1-x^n)^n.
MAPLE
add( d*binomial(n/d+d-2, d-1), d=numtheory[divisors](n) ) ;
PROG
(PARI) N=66; x='x+O('x^N); Vec(sum(k=1, N, k*x^k/(1-x^k)^k)) \\ Seiichi Manyama, Sep 03 2019
CROSSREFS
KEYWORD
AUTHOR
R. J. Mathar, Feb 21 2009
STATUS
approved