A320207 Number of sets of nonempty words with a total of n letters over senary alphabet such that all letters occur at least once in the set.

4051, 111396, 1830822, 23420022, 257667120, 2564003346, 23761098837, 208907298660, 1764392910027, 14440938630576, 115269796672350, 901599089475150, 6935143271107130, 52608326918749428, 394424679767297550, 2927811687630339744, 21547773469006784856

Offset

6,1

Links

Alois P. Heinz, Table of n, a(n) for n = 6..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))(6):
seq(a(n), n=6..25);

Crossrefs

Column k=6 of A319501.

Cf. A320216.

Sequence in context: A251032 A035782 A108006 * A320216 A246801 A020430

Adjacent sequences: A320204 A320205 A320206 * A320208 A320209 A320210

Keyword

nonn

Author

Alois P. Heinz, Oct 07 2018

Status

approved