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 A140903 #7 Jan 17 2025 09:28:38
%S A140903 1,84,2520,41580,457380,3737448,24293412,131589315,614083470,
%T A140903 2530768240,9386849472,31803696288,99604982880,291153026880,
%U A140903 800670823920,2085276513474,5172303508911,12276881393700,27999904933000,61578738292500,130994770549500,270273795363000
%N A140903 Number of 3 X 6 matrices with elements in 0..n with each row and each column in nondecreasing order. 3,6,n can be permuted, see formula.
%H A140903 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 A140903 (empirical) set p,q,r to n,6,3 (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 A140903 nonn
%O A140903 0,2
%A A140903 _R. H. Hardin_, Jul 05 2008