A140941 - OEIS

%I #8 Jan 28 2025 10:59:31

%S 1,167960,4936848280,44648855844320,165848175033726640,

%T 303282730418598205184,309490028060407426691200

%N Number of 9 X 11 matrices with elements in 0..n with each row and each column in nondecreasing order. 9,11,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,11,9 (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,more

%O 0,2

%A _R. H. Hardin_, Jul 05 2008