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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.
3
4051, 111396, 1830822, 23420022, 257667120, 2564003346, 23761098837, 208907298660, 1764392910027, 14440938630576, 115269796672350, 901599089475150, 6935143271107130, 52608326918749428, 394424679767297550, 2927811687630339744, 21547773469006784856
OFFSET
6,1
LINKS
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
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 07 2018
STATUS
approved