OFFSET
9,10
LINKS
Alois P. Heinz, Table of n, a(n) for n = 9..10000
FORMULA
a(n) = [x^n y^9] 1/Product_{j>=1} (1-y*x^A000217(j)).
MAPLE
h:= proc(n) option remember; `if`(n<1, 0,
`if`(issqr(8*n+1), n, h(n-1)))
end:
b:= proc(n, i, k) option remember; `if`(n=0, `if`(k=0, 1, 0), `if`(
k>n or i*k<n, 0, b(n, h(i-1), k)+b(n-i, h(min(n-i, i)), k-1)))
end:
a:= n-> b(n, h(n), 9):
seq(a(n), n=9..120);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 28 2018
STATUS
approved