A223964 Number of 4Xn 0..3 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.

256, 5864, 41006, 176893, 594286, 1718057, 4500818, 10981150, 25334630, 55772240, 117841845, 239976226, 472531867, 902107834, 1673660678, 3023882381, 5330533450, 9183978785, 15489123731, 25608363453, 41559120445, 66283141375

Offset: 1

Author

R. H. Hardin Mar 29 2013

Keywords

• nonn

Comments

Row 4 of A223961

Examples

			Some solutions for n=3
..0..1..1....1..2..2....0..1..1....0..0..1....0..1..2....0..0..2....0..1..2
..0..2..3....1..2..3....1..1..2....1..3..3....0..3..3....0..2..3....0..3..3
..2..3..3....1..1..3....0..2..2....1..1..3....1..2..3....0..1..2....1..1..3
..2..2..3....0..1..3....0..2..3....0..1..2....1..3..3....1..3..3....0..2..2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

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