A224376 Number of 4 X n 0..2 arrays with rows unimodal and antidiagonals nondecreasing.

81, 1944, 15540, 77793, 311367, 1092281, 3518302, 10643789, 30548895, 83538706, 218139823, 544930741, 1304961768, 3002671615, 6654904188, 14242413828, 29504608642, 59301307852, 115889490174, 220645337145, 410024971049

Offset: 1

Author

R. H. Hardin, Apr 05 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Row 4 of A224374.

Formula

Empirical: a(n) = (1/106748928000)*n^16 + (1/1482624000)*n^15 + (7/266872320)*n^14 + (127/197683200)*n^13 + (315179/28740096000)*n^12 + (24499/177408000)*n^11 + (89507/65318400)*n^10 + (112109/9676800)*n^9 + (68633371/746496000)*n^8 + (11395841/16128000)*n^7 + (6723664007/1437004800)*n^6 + (295741651/13305600)*n^5 + (262119224347/5189184000)*n^4 - (16331232329/1297296000)*n^3 + (12600631/343200)*n^2 + (38790413/360360)*n - 166 for n>2.