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Number of 4Xn 0..3 arrays with antidiagonals unimodal and rows and diagonals nondecreasing
1

%I #4 Mar 29 2013 21:50:09

%S 256,5864,41006,176893,594286,1718057,4500818,10981150,25334630,

%T 55772240,117841845,239976226,472531867,902107834,1673660678,

%U 3023882381,5330533450,9183978785,15489123731,25608363453,41559120445,66283141375

%N Number of 4Xn 0..3 arrays with antidiagonals unimodal and rows and diagonals nondecreasing

%C Row 4 of A223961

%H R. H. Hardin, <a href="/A223964/b223964.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (1/1036800)*n^12 + (1/34560)*n^11 + (4379/7257600)*n^10 + (757/80640)*n^9 + (257687/2419200)*n^8 + (82939/80640)*n^7 + (8187071/1036800)*n^6 + (1661651/34560)*n^5 + (117000427/453600)*n^4 + (10787803/20160)*n^3 - (153061829/50400)*n^2 + (3421969/840)*n + 275 for n>5

%e Some solutions for n=3

%e ..0..1..1....1..2..2....0..1..1....0..0..1....0..1..2....0..0..2....0..1..2

%e ..0..2..3....1..2..3....1..1..2....1..3..3....0..3..3....0..2..3....0..3..3

%e ..2..3..3....1..1..3....0..2..2....1..1..3....1..2..3....0..1..2....1..1..3

%e ..2..2..3....0..1..3....0..2..3....0..1..2....1..3..3....1..3..3....0..2..2

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 29 2013