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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.
3
4596553, 263460321, 8549512506, 207037303758, 4169086763787, 73865658618900, 1191183607371897, 17876336340787308, 253521082577243286, 3435636331820210328, 44859666267675306756, 567955878004442678319, 7007036376866803617768, 84571686324119453047650
OFFSET
9,1
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))(9):
seq(a(n), n=9..25);
CROSSREFS
Column k=9 of A319501.
Cf. A320219.
Sequence in context: A152964 A129931 A206195 * A320219 A265448 A272701
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 07 2018
STATUS
approved