A320210 Number of sets of nonempty words with a total of n letters over nonary alphabet such that all letters occur at least once in the set.

4596553, 263460321, 8549512506, 207037303758, 4169086763787, 73865658618900, 1191183607371897, 17876336340787308, 253521082577243286, 3435636331820210328, 44859666267675306756, 567955878004442678319, 7007036376866803617768, 84571686324119453047650

Offset: 9

Author

Alois P. Heinz, Oct 07 2018

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 9..1000

Crossrefs

Column k=9 of A319501.

Cf. A320219.

Programs

Maple

h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
      add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
    end:
a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(9):
seq(a(n), n=9..25);