A224058 Number of nX2 0..3 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

16, 160, 984, 4580, 17723, 59792, 180821, 499357, 1276595, 3053471, 6892199, 14784563, 30317821, 59727346, 113515445, 208880837, 373286086, 649594326, 1103335758, 1832822970, 2983026931, 4764357840, 7477772697, 11547960881

Offset: 1

Author

R. H. Hardin Mar 30 2013

Keywords

• nonn

Comments

Column 2 of A224064

Examples

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

Links

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

Formula

Empirical: a(n) = (1/19160064)*n^12 + (1/456192)*n^11 + (2287/43545600)*n^10 + (215/290304)*n^9 + (2861/414720)*n^8 + (7187/161280)*n^7 + (10695901/43545600)*n^6 + (212027/207360)*n^5 + (6072841/2177280)*n^4 + (1652783/362880)*n^3 + (1059277/237600)*n^2 + (26023/13860)*n + 1