cp's OEIS Frontend

A320215 Number of multisets of nonempty words with a total of n letters over quinary alphabet such that all letters occur at least once in the multiset.

%I A320215 #4 Oct 07 2018 14:43:35
%S A320215 501,10310,129485,1285815,11117600,87804401,651039050,4610303390,
%T A320215 31536998095,210038354645,1369653353001,8781196628665,55523386000940,
%U A320215 347061871472795,2148545319437735,13192142317933416,80429793804860995,487358723056001905,2937204731254087895
%N A320215 Number of multisets of nonempty words with a total of n letters over quinary alphabet such that all letters occur at least once in the multiset.
%H A320215 Alois P. Heinz, <a href="/A320215/b320215.txt">Table of n, a(n) for n = 5..1000</a>
%p A320215 b:= proc(n, k) option remember; `if`(n=0, 1, add(add(
%p A320215       d*k^d, d=numtheory[divisors](j))*b(n-j, k), j=1..n)/n)
%p A320215     end:
%p A320215 a:= n-> (k-> add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(5):
%p A320215 seq(a(n), n=5..25);
%Y A320215 Column k=5 of A257740.
%Y A320215 Cf. A320206.
%K A320215 nonn
%O A320215 5,1
%A A320215 _Alois P. Heinz_, Oct 07 2018