A185471 Number of (n+2)X5 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order

13659, 76309, 308692, 1043186, 3097348, 8297059, 20411234, 46732687, 100636591, 205574323, 401123377, 751921908, 1360579387, 2385984676, 4068843506, 6766785098, 11002001311, 17525142877, 27400120766, 42115574722, 63730107482

Offset

1,1

Comments

Column 3 of A185477

Links

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

Formula

Empirical: a(n) = (1/444787200)*n^13

+ (107/479001600)*n^12

+ (11/1088640)*n^11

+ (3623/6220800)*n^10

+ (78227/3628800)*n^9

+ (6420917/14515200)*n^8

+ (148481/27216)*n^7

+ (1861160843/43545600)*n^6

+ (4966108109/21772800)*n^5

+ (1448539279/1555200)*n^4

+ (3663351401/1330560)*n^3

+ (2013261953/415800)*n^2

+ (15650889/3640)*n

+ 556

Example

Some solutions for 4X5
..0..0..0..1..2....0..0..0..0..0....0..0..0..0..2....0..0..0..1..1
..0..0..1..1..2....0..0..1..2..2....0..0..0..2..2....0..0..0..1..2
..0..1..1..2..0....1..1..2..1..1....0..0..1..0..1....0..1..1..1..2
..2..1..2..0..2....2..2..2..1..2....1..2..2..1..1....1..1..2..2..2

Crossrefs

Sequence in context: A206091 A218456 A224971 * A203727 A088870 A047827

Adjacent sequences: A185468 A185469 A185470 * A185472 A185473 A185474

Keyword

nonn

Author

R. H. Hardin Jan 28 2011

Status

approved