A184569 Number of (n+2)X6 0..3 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.

2430950, 37767705, 380532059, 2943827443, 18803004899, 103444456133, 503785839330, 2213469458762, 8896632071640, 33064363109286, 114609983293024, 373179093576287, 1148351083047878, 3357036249298069, 9365408840621016

Offset: 1

Author

R. H. Hardin Jan 17 2011

Keywords

• nonn

Comments

Column 4 of A184574

Examples

			Some solutions for 4X6
..0..0..0..0..1..3....0..0..0..0..0..2....0..0..0..0..0..3....0..0..0..0..0..1
..0..0..0..0..3..3....0..0..0..0..0..2....0..0..0..0..0..3....0..0..0..0..2..2
..0..0..0..2..0..1....0..0..0..1..2..2....0..0..1..2..2..3....0..0..0..1..1..1
..0..0..0..3..2..2....0..0..2..3..2..1....0..0..2..2..3..0....0..0..2..1..1..2
		

Links

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

Formula

Empirical: a(n) = (1877/33876482734634873389056000000)*n^28

+ (11987/622221111452477266329600000)*n^27

+ (737071/230452263500917506048000000)*n^26

+ (2523251/7445380820798873272320000)*n^25

+ (720529321/24817936069329577574400000)*n^24

+ (226209029/96693257412972380160000)*n^23

+ (428601636263/2517761630221841203200000)*n^22

+ (895861352717/88285148072713912320000)*n^21

+ (6657779572813/14013515567097446400000)*n^20

+ (513500327060663/29428382690904637440000)*n^19

+ (28902349506792719/56791615719289651200000)*n^18

+ (29102175898763483/2433926387969556480000)*n^17

+ (69715669922508077933/304002178262079897600000)*n^16

+ (142038276256570683601/39085994347981701120000)*n^15

+ (298469360258931891817/6204126086981222400000)*n^14

+ (3766091227509416251/7008426456514560000)*n^13

+ (72461481986205915365513/14197903929822412800000)*n^12

+ (2288207763441237912457/55316508817489920000)*n^11

+ (36755880863016765433108943/128749174272707788800000)*n^10

+ (27526974266867197736771411/16553465263633858560000)*n^9

+ (97026713608751439944355719/12042864940474368000000)*n^8

+ (268702236610212374702478103/8430005458332057600000)*n^7

+ (905845241244834660379823869/8976394701001728000000)*n^6

+ (9642800930818575777090611/38470263004293120000)*n^5

+ (1335942364702678794101791/2801275438241280000)*n^4

+ (437836547410214702956529/663029154051264000)*n^3

+ (23010191291418229189/38588998383936)*n^2

+ (1159084670787299/4015671660)*n

+ 15261