This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A375693 #18 Aug 27 2024 14:51:53
%S A375693 1,0,5,1622,62924817,623302086965044,2670169511426774520697375,
%T A375693 7363615066099523741730150062678073534,
%U A375693 18165723898797467057177720588121375861340650728031233,53130688704554689391452744667655289291011354800478739192999936981375688
%N A375693 Number of multiset permutations of {{1}^n, {2}^n, ..., {n}^n} with no fixed n-tuple {j}^n.
%H A375693 Alois P. Heinz, <a href="/A375693/b375693.txt">Table of n, a(n) for n = 0..26</a>
%F A375693 a(n) = Sum_{j=0..n} (-1)^(n-j)*binomial(n,j)*(n*j)!/n!^j.
%F A375693 a(n) mod 2 = 1 - (n mod 2) = A059841(n).
%e A375693 a(2) = 5: 1212, 1221, 2112, 2121, 2211.
%p A375693 a:= n-> add((-1)^(n-j)*binomial(n, j)*(n*j)!/n!^j, j=0..n):
%p A375693 seq(a(n), n=0..10);
%Y A375693 Main diagonal of A375694.
%Y A375693 Cf. A034841, A059841, A306241, A375778.
%K A375693 nonn
%O A375693 0,3
%A A375693 _Alois P. Heinz_, Aug 24 2024