OFFSET
9,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 9..450
FORMULA
E.g.f.: x^9 * Product_{i=1..9} (i-1)!/(i!-x^i).
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
b(n, i-1)+`if`(i>n, 0, binomial(n, i)*b(n-i, i))))
end:
a:= n-> (k-> b(n, k) -b(n, k-1))(9):
seq(a(n), n=9..30);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 01 2016
STATUS
approved