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A185470
Number of (n+2)X4 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order
1
4594, 21834, 76309, 225672, 594798, 1433903, 3212372, 6763143, 13496424, 25706057, 46997040, 82868632, 141494158, 234746166, 379524035, 599450565, 927014574, 1406248164, 2096040183, 3074201592, 4442414038, 6332210033
OFFSET
1,1
COMMENTS
Column 2 of A185477
LINKS
FORMULA
Empirical: a(n) = (1/9979200)*n^11
+ (29/3628800)*n^10
+ (257/241920)*n^9
+ (4621/120960)*n^8
+ (400927/604800)*n^7
+ (1134257/172800)*n^6
+ (31386443/725760)*n^5
+ (20355493/90720)*n^4
+ (80111509/100800)*n^3
+ (40459121/25200)*n^2
+ (7603747/4620)*n
+ 273
EXAMPLE
Some solutions for 6X4
..0..0..0..0....0..0..0..0....0..0..0..1....0..0..0..0....0..0..0..0
..0..0..0..1....0..0..0..1....0..0..0..1....0..0..0..2....0..0..0..1
..0..0..1..1....0..0..1..2....0..0..0..2....0..0..1..1....0..0..0..1
..0..0..1..2....0..0..1..2....0..0..1..2....1..1..2..2....0..0..1..1
..0..0..1..2....0..1..1..1....0..1..2..1....1..2..1..2....0..1..0..1
..0..0..2..1....1..1..2..1....1..2..2..1....1..2..2..0....2..2..2..1
CROSSREFS
Sequence in context: A205231 A231022 A251385 * A004537 A204655 A204652
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 28 2011
STATUS
approved