cp's OEIS Frontend

A320211 Number of sets of nonempty words with a total of n letters over denary alphabet such that all letters occur at least once in the set.

%I A320211 #7 Oct 07 2018 14:54:41
%S A320211 58941091,4097382940,159454061270,4587784661870,108909499300650,
%T A320211 2259736176893470,42433681634931005,737876928284127870,
%U A320211 12073172284265618005,188049325030487680920,2812707955072045999940,40672129029056125818340,571583937930987524954470
%N A320211 Number of sets of nonempty words with a total of n letters over denary alphabet such that all letters occur at least once in the set.
%H A320211 Alois P. Heinz, <a href="/A320211/b320211.txt">Table of n, a(n) for n = 10..975</a>
%p A320211 h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
%p A320211       add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
%p A320211     end:
%p A320211 a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(10):
%p A320211 seq(a(n), n=10..25);
%Y A320211 Column k=10 of A319501.
%Y A320211 Cf. A320220.
%K A320211 nonn
%O A320211 10,1
%A A320211 _Alois P. Heinz_, Oct 07 2018