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Number of 4 X 6 matrices with elements in 0..n with each row and each column in nondecreasing order. 4,6,n can be permuted, see formula.
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%I #7 Jan 17 2025 09:28:41

%S 1,210,13860,457380,9343620,133613766,1447482465,12544848030,

%T 90474964580,559299781040,3031952379456,14675134144320,64344818940480,

%U 258616676126160,962206162645860,3341308066756506,10904939897954025,33648885753232750,98669664990682500

%N Number of 4 X 6 matrices with elements in 0..n with each row and each column in nondecreasing order. 4,6,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,6,4 (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

%O 0,2

%A _R. H. Hardin_, Jul 05 2008