A185472 Number of (n+2)X6 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order

34779, 225672, 1043186, 3959167, 12990375, 37961900, 100908633, 247920339, 570069808, 1239033996, 2565887950, 5095678058, 9756244258, 18087995239, 32592776835, 57255685167, 98315034745, 165384433476, 273069215898

Offset

1,1

Comments

Column 4 of A185477

Links

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

Formula

Empirical: a(n) = (1/27243216000)*n^15

+ (97/21794572800)*n^14

+ (1549/6227020800)*n^13

+ (4127/479001600)*n^12

+ (676031/2395008000)*n^11

+ (54763/6220800)*n^10

+ (60678553/304819200)*n^9

+ (904333037/304819200)*n^8

+ (910283537/31104000)*n^7

+ (8446896821/43545600)*n^6

+ (213392977159/239500800)*n^5

+ (52396736149/17107200)*n^4

+ (70560211894163/9081072000)*n^3

+ (1840763445463/151351200)*n^2

+ (1738288907/180180)*n

+ 1019

Example

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

Crossrefs

Sequence in context: A256900 A236141 A103911 * A116016 A253117 A236591

Adjacent sequences: A185469 A185470 A185471 * A185473 A185474 A185475

Keyword

nonn

Author

R. H. Hardin Jan 28 2011

Status

approved