A224264 Number of 4Xn 0..2 arrays with rows and antidiagonals unimodal and columns nondecreasing

15, 225, 2017, 12467, 59855, 240829, 850875, 2717731, 8000608, 22004896, 57114321, 140968221, 332855049, 755508149, 1654943378, 3509994992, 7227765020, 14484196632, 28304567857, 54032736159, 100918573991, 184671328897

Offset

1,1

Comments

Row 4 of A224262

Links

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

Formula

Empirical: a(n) = (1/106748928000)*n^16 + (1/13343616000)*n^15 + (71/9340531200)*n^14 + (341/3396556800)*n^13 + (70619/28740096000)*n^12 + (6403/186624000)*n^11 + (29921/65318400)*n^10 + (938611/261273600)*n^9 + (179393437/5225472000)*n^8 + (211646789/1306368000)*n^7 + (955811279/1437004800)*n^6 + (152465767/51321600)*n^5 - (11075280679/15567552000)*n^4 - (274011991/117936000)*n^3 + (8155853/123552)*n^2 - (184217/936)*n + 242 for n>2

Example

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

Crossrefs

Sequence in context: A207738 A221966 A208080 * A223921 A224191 A224349

Adjacent sequences: A224261 A224262 A224263 * A224265 A224266 A224267

Keyword

nonn

Author

R. H. Hardin Apr 02 2013

Status

approved