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

9,1

Links

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

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);

Crossrefs

Column k=9 of A319501.

Cf. A320219.

Sequence in context: A152964 A129931 A206195 * A320219 A265448 A272701

Adjacent sequences: A320207 A320208 A320209 * A320211 A320212 A320213

Keyword

nonn

Author

Alois P. Heinz, Oct 07 2018

Status

approved