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%I #7 Oct 07 2018 14:50:41
%S 394353,18235680,484092688,9697863856,163046201132,2430540970008,
%T 33194557467204,424251626739144,5148887208055692,59963231946871288,
%U 675318621308265328,7398542789316786184,79210967706138213860,831754864387299725168,8590788276593760698232
%N 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.
%H Alois P. Heinz, <a href="/A320209/b320209.txt">Table of n, a(n) for n = 8..1000</a>
%p h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
%p add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
%p end:
%p a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(8):
%p seq(a(n), n=8..25);
%Y Column k=8 of A319501.
%Y Cf. A320218.
%K nonn
%O 8,1
%A _Alois P. Heinz_, Oct 07 2018
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