OFFSET
7,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 7..5000
FORMULA
G.f.: (-1 + Product_{k>=1} 1 / (1 - x^k)^k)^7. - Ilya Gutkovskiy, Jan 30 2021
MAPLE
b:= proc(n, k) option remember; `if`(n=0, 1, k*add(
b(n-j, k)*numtheory[sigma][2](j), j=1..n)/n)
end:
a:= n-> (k-> add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(7):
seq(a(n), n=7..35);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Nov 22 2018
STATUS
approved