A224357 Number of 6Xn 0..2 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.

729, 46656, 349280, 1351748, 4231138, 12340932, 34697869, 94262290, 246254814, 616242552, 1475123504, 3379586703, 7423803582, 15672970622, 31884279651, 62668814332, 119312143790, 220555944774, 396752366132, 695942226325

Offset: 1

Author

R. H. Hardin Apr 04 2013

Keywords

• nonn

Comments

Row 6 of A224353

Examples

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

Links

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

Formula

Empirical: a(n) = (761/8553600)*n^12 + (1733/3326400)*n^11 + (1459/108864)*n^10 + (4187/40320)*n^9 + (1551227/1814400)*n^8 + (72841/12600)*n^7 + (1802801/19440)*n^6 - (66259339/120960)*n^5 + (9020552353/1360800)*n^4 - (817656577/50400)*n^3 + (5508355001/83160)*n^2 - (57456263/1540)*n - 269256 for n>7