%I #4 Oct 01 2013 14:09:37
%S 2432,384183,15106048,266515625,2805425280,20610104767,116211580928,
%T 535021318017,2098414000000,7227967108439,22362655260672,
%U 63219695614153,165498794685056,405459218109375,937601561264128,2060839403682497
%N Number of 4X4 0..n arrays with corresponding row and column sums equal
%C Row 4 of A229870
%H R. H. Hardin, <a href="/A229871/b229871.txt">Table of n, a(n) for n = 1..73</a>
%F Empirical: a(n) = (29/140)*n^13 + (377/140)*n^12 + (3449/210)*n^11 + (13057/210)*n^10 + (34249/210)*n^9 + (21941/70)*n^8 + (6826/15)*n^7 + (53206/105)*n^6 + (60773/140)*n^5 + (119003/420)*n^4 + (28807/210)*n^3 + (9791/210)*n^2 + (348/35)*n + 1
%e Some solutions for n=4
%e ..0..0..0..0....0..0..0..1....0..0..0..1....0..0..1..1....0..0..1..1
%e ..0..1..2..3....0..0..4..2....0..1..1..3....0..1..2..1....0..1..0..2
%e ..0..4..0..0....1..4..0..1....1..4..2..0....1..3..4..3....1..2..0..0
%e ..0..1..2..3....0..2..2..3....0..0..4..3....1..0..4..1....1..0..2..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Oct 01 2013