A224266 Number of 6 X n 0..2 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.

28, 784, 11990, 116692, 816361, 4480391, 20568693, 82733667, 301228048, 1015242774, 3216158234, 9677475342, 27865037554, 77192516888, 206580752375, 535811566173, 1350500930653, 3315175437671, 7940967421582, 18591190564502, 42601309065441, 95664964823719, 210745412046812

Offset: 1

Author

R. H. Hardin, Apr 02 2013

Keywords

• nonn

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..204

Crossrefs

Row 6 of A224262.

Formula

Empirical: a(n) = (1/35608838483312640000)*n^24 - (1/989134402314240000)*n^23 + (601/8515157028618240000)*n^22 - (547/425757851430912000)*n^21 + (13921/270322445352960000)*n^20 - (200479/608225502044160000)*n^19 + (115963/6590678814720000)*n^18 + (117617/1244905998336000)*n^17 + (252537361/52725430517760000)*n^16 + (879308299/13181357629440000)*n^15 + (134826737/114124308480000)*n^14 - (85421863/37661021798400)*n^13 + (32134877807171/52725430517760000)*n^12 - (2871377051923/488198430720000)*n^11 + (1288837369490701/13181357629440000)*n^10 - (184837585191797/329533940736000)*n^9 + (23642024191142869/5335311421440000)*n^8 - (12049177715869673/1000370891520000)*n^7 + (510702403798050053/44349776190720000)*n^6 + (72547792289651647/739162936512000)*n^5 - (132132690434377993/149325845760000)*n^4 + (83209134313815637/41064607584000)*n^3 + (10053832694553481/264561897600)*n^2 - (1502154800678423/5354228880)*n + 570714 for n>6.

Extensions

Name corrected by Andrew Howroyd, Mar 18 2025