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Number of 5 X 8 matrices with elements in 0..n with each row and each column in nondecreasing order. 5,8,n can be permuted, see formula.
0

%I #7 Jan 19 2025 11:09:17

%S 1,1287,429429,61408347,4789851066,235234907908,7997986868872,

%T 201299981193168,3940599631842016,62305564808355232,

%U 819557814017595744,9183250377581777952,89360090212622685456,767243308499780749560,5890437072025627650100

%N Number of 5 X 8 matrices with elements in 0..n with each row and each column in nondecreasing order. 5,8,n can be permuted, see formula.

%H Feihu Liu, Guoce Xin, and Chen Zhang, <a href="https://arxiv.org/abs/2412.18744">Ehrhart Polynomials of Order Polytopes: Interpreting Combinatorial Sequences on the OEIS</a>, arXiv:2412.18744 [math.CO], 2024. See p. 25.

%F (empirical) set p,q,r to n,8,5 (in any order) in s=p+q+r-1; a(n) = product {i in 0..r-1} (binomial(s,p+i)*i!/(s-i)^(r-i-1))

%K nonn,changed

%O 0,2

%A _R. H. Hardin_, Jul 05 2008