A320208 Number of sets of nonempty words with a total of n letters over septenary alphabet such that all letters occur at least once in the set.

37633, 1366057, 28969248, 470004045, 6470660266, 79706067707, 906335330250, 9706198156760, 99243640018075, 978284068984075, 9363362648969343, 87485517250169934, 801259222264152813, 7216852772737393058, 64088034265985397794, 562287261308092526759

Offset

7,1

Links

Alois P. Heinz, Table of n, a(n) for n = 7..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))(7):
seq(a(n), n=7..25);

Crossrefs

Column k=7 of A319501.

Cf. A320217.

Sequence in context: A284080 A092682 A236122 * A320217 A236883 A048526

Adjacent sequences: A320205 A320206 A320207 * A320209 A320210 A320211

Keyword

nonn

Author

Alois P. Heinz, Oct 07 2018

Status

approved