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

1,1

Comments

Column 4 of A184574

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

Example

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

Crossrefs

Sequence in context: A104941 A251805 A184669 * A210153 A144588 A022216

Adjacent sequences: A184566 A184567 A184568 * A184570 A184571 A184572

Keyword

nonn

Author

R. H. Hardin Jan 17 2011

Status

approved