cp's OEIS Frontend

A320219 Number of multisets of nonempty words with a total of n letters over nonary alphabet such that all letters occur at least once in the multiset.

%I A320219 #4 Oct 07 2018 14:52:24
%S A320219 4596553,267009498,8759066967,214009517289,4341556649997,
%T A320219 77402791217151,1254856577798877,18917548771779954,269340155175667401,
%U A320219 3662449762145471938,47963634774469915293,608844238997012412552,7528868495379885600462,91056717786483891773442
%N A320219 Number of multisets of nonempty words with a total of n letters over nonary alphabet such that all letters occur at least once in the multiset.
%H A320219 Alois P. Heinz, <a href="/A320219/b320219.txt">Table of n, a(n) for n = 9..1000</a>
%p A320219 b:= proc(n, k) option remember; `if`(n=0, 1, add(add(
%p A320219       d*k^d, d=numtheory[divisors](j))*b(n-j, k), j=1..n)/n)
%p A320219     end:
%p A320219 a:= n-> (k-> add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(9):
%p A320219 seq(a(n), n=9..25);
%Y A320219 Column k=9 of A257740.
%Y A320219 Cf. A320210.
%K A320219 nonn
%O A320219 9,1
%A A320219 _Alois P. Heinz_, Oct 07 2018