A223929 Number of nX4 0..2 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

46, 698, 4498, 21334, 86439, 316136, 1065625, 3337831, 9773219, 26903878, 70024867, 173255292, 409514526, 928832014, 2029581476, 4287303027, 8781854785, 17488776976, 33939319272, 64311697250, 119202262153, 216450903569

Offset: 1

Author

R. H. Hardin Mar 29 2013

Keywords

• nonn

Comments

Column 4 of A223933

Examples

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

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 + (1/116756640)*n^14 + (4003/37362124800)*n^13 + (97199/28740096000)*n^12 + (670871/14370048000)*n^11 + (94057/130636800)*n^10 - (113957/261273600)*n^9 + (565001317/5225472000)*n^8 - (887457691/1306368000)*n^7 + (3190047029/359251200)*n^6 - (36838723231/718502400)*n^5 + (4745796217531/15567552000)*n^4 - (170787179737/162162000)*n^3 + (51300697729/21621600)*n^2 - (74839579/180180)*n - 7017 for n>6