A223983 Number of nX4 0..3 arrays with rows unimodal and columns nondecreasing.

130, 3526, 44803, 358118, 2086196, 9647292, 37395816, 126087157, 379654704, 1040942916, 2637614941, 6248087300, 13964013792, 29662913488, 60254807616, 117633453657, 221649696158, 404535879938, 717351048575, 1239192239626

Offset: 1

Author

R. H. Hardin Mar 30 2013

Keywords

• nonn

Comments

Column 4 of A223987

Examples

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

Links

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

Formula

Empirical: a(n) = (3551/47900160)*n^12 + (89357/39916800)*n^11 + (132341/4354560)*n^10 + (177787/725760)*n^9 + (1892753/1451520)*n^8 + (5834147/1209600)*n^7 + (11057083/870912)*n^6 + (17370313/725760)*n^5 + (6973385/217728)*n^4 + (26874943/907200)*n^3 + (186503/10395)*n^2 + (8831/1386)*n + 1