A223862 Number of nX6 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.

610, 52591, 1477240, 22852913, 243933798, 1989679315, 13140481520, 73068868012, 352040804450, 1502130487437, 5774921786002, 20281095690376, 65798275499953, 199037907806762, 565735226772194, 1520829902726663, 3888227083552907

Offset: 1

Author

R. H. Hardin Mar 28 2013

Keywords

• nonn

Comments

Column 6 of A223864

Examples

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

Links

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

Formula

Empirical: a(n) = (42587101/1600593426432000)*n^18 + (42587101/44460928512000)*n^17 + (315292339/15692092416000)*n^16 + (41939983/145297152000)*n^15 + (4407829651/1426553856000)*n^14 + (41324477/1596672000)*n^13 + (19314677849/113164128000)*n^12 + (2898049019/3143448000)*n^11 + (876424981241/219469824000)*n^10 + (28801840747/2032128000)*n^9 + (50450804070829/1207084032000)*n^8 + (17909311831/177408000)*n^7 + (265168304450783/1471133664000)*n^6 + (27553165793177/163459296000)*n^5 - (2984221796923/29719872000)*n^4 - (816413565637/1009008000)*n^3 - (1198736836439/7718911200)*n^2 + (2348655877/471240)*n - 5035 for n>4