A184566 Number of (n+2)X3 0..3 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.

14178, 102445, 545662, 2430950, 9496395, 33351260, 107058241, 318063303, 883398416, 2312834051, 5747404508, 13634816674, 31030883261, 68030181122, 144179542873, 296289041222, 591935421670, 1152308627603, 2190104262402

Offset: 1

Author

R. H. Hardin Jan 17 2011

Keywords

• nonn

Comments

Column 1 of A184574

Examples

			Some solutions for 4X3
..0..1..3....0..1..1....0..0..2....0..0..0....0..1..3....0..0..3....0..1..1
..0..2..3....0..1..2....0..1..2....1..1..3....0..3..3....0..1..3....1..1..1
..3..2..3....2..2..3....3..0..0....1..2..0....2..0..0....0..3..3....1..2..3
..3..3..1....2..3..1....3..3..1....3..0..0....3..1..3....2..0..1....2..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = (1/121645100408832000)*n^19

+ (53/3201186852864000)*n^18

+ (5743/2134124568576000)*n^17

+ (12931/62768369664000)*n^16

+ (621041/62768369664000)*n^15

+ (10734523/31384184832000)*n^14

+ (1720232317/188305108992000)*n^13

+ (127448011/658409472000)*n^12

+ (6294370109/1931334451200)*n^11

+ (18970604773/438939648000)*n^10

+ (4321841102639/9656672256000)*n^9

+ (17491957547611/4828336128000)*n^8

+ (1086794057312713/47076277248000)*n^7

+ (2752481070552527/23538138624000)*n^6

+ (1237909924891457/2615348736000)*n^5

+ (1921023328483453/1307674368000)*n^4

+ (249101413506019/77189112000)*n^3

+ (12857906145353/2806876800)*n^2

+ (288855292519/77597520)*n

+ 561