A224266 Number of 6Xn 0..2 arrays with rows 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

Offset

1,1

Comments

Row 6 of A224262

Links

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

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

Example

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

Crossrefs

Sequence in context: A208043 A208032 A264368 * A223923 A224351 A224193

Adjacent sequences: A224263 A224264 A224265 * A224267 A224268 A224269

Keyword

nonn

Author

R. H. Hardin Apr 02 2013

Status

approved