A185475 Number of (n+2)X9 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.

336690, 3212372, 20411234, 100908633, 416227164, 1497314456, 4845252741, 14425457557, 40183952539, 106069534256, 267851235385, 651716593546, 1535886293189, 3519099305097, 7860273371841, 17147427400925, 36585315520514

Offset: 1

Author

R. H. Hardin Jan 28 2011

Keywords

• nonn

Comments

Column 7 of A185477

Examples

			Some solutions for 4X9
..0..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0..1
..0..0..0..0..0..0..0..1..2....0..0..0..0..0..0..0..0..1
..0..0..0..0..0..1..1..1..0....0..0..0..0..0..1..1..2..2
..0..0..0..1..2..1..2..2..0....0..0..0..0..1..1..2..1..2
		

Links

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

Formula

Empirical: a(n) = (1/25519951134720000)*n^21

+ (1/127919554560000)*n^20

+ (1877/2551995113472000)*n^19

+ (101861/2328135892992000)*n^18

+ (10763959/5820339732480000)*n^17

+ (24725641/418455797760000)*n^16

+ (836589317/564915326976000)*n^15

+ (22655691343/753220435968000)*n^14

+ (5887296211331/11298306539520000)*n^13

+ (436620904451/52672757760000)*n^12

+ (3650470717199/28970016768000)*n^11

+ (2036750095277/1170505728000)*n^10

+ (1572848084986607/79009136640000)*n^9

+ (1160407108626427/6584094720000)*n^8

+ (2296534278781759/1975228416000)*n^7

+ (525799308273622787/94152554496000)*n^6

+ (25696337451699745273/1333827855360000)*n^5

+ (2682952836795541619/55576160640000)*n^4

+ (124299364108443341/1407929402880)*n^3

+ (73695052155737/701719200)*n^2

+ (1503827501467/23279256)*n

+ 4299