A223720 Number of n X 3 0..2 arrays with rows, antidiagonals and columns unimodal.

22, 484, 5883, 46613, 273562, 1285547, 5087912, 17557701, 54161878, 152154419, 394849354, 957192985, 2187192034, 4745347460, 9834757897, 19568773673, 37541913638, 69694254022, 125590862829, 220277446621, 376922731034

Offset: 1

Author

R. H. Hardin, Mar 26 2013

Keywords

• nonn

Comments

Column 3 of A223725.

Examples

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

Links

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

Crossrefs

Cf. A223725.

Formula

Empirical: a(n) = (5051/239500800)*n^12 + (61/177408)*n^11 + (91271/21772800)*n^10 + (27/896)*n^9 + (1198121/7257600)*n^8 + (1087/1792)*n^7 + (36617153/21772800)*n^6 + (63719/20160)*n^5 + (26821099/5443200)*n^4 + (305/56)*n^3 + (149993/207900)*n^2 + (3277/770)*n + 1.