A320209 Number of sets of nonempty words with a total of n letters over octonary alphabet such that all letters occur at least once in the set.

394353, 18235680, 484092688, 9697863856, 163046201132, 2430540970008, 33194557467204, 424251626739144, 5148887208055692, 59963231946871288, 675318621308265328, 7398542789316786184, 79210967706138213860, 831754864387299725168, 8590788276593760698232

Offset: 8

Author

Alois P. Heinz, Oct 07 2018

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 8..1000

Crossrefs

Column k=8 of A319501.

Cf. A320218.

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))(8):
seq(a(n), n=8..25);