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A219847 Number of nX3 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX3 array 1
6, 17, 65, 225, 669, 1815, 4617, 11125, 25523, 55964, 117681, 238066, 464687, 877568, 1607502, 2862716, 4966875, 8412215, 13932550, 22602023, 35966785, 56218309, 86418799, 130791159, 195088267, 287058878, 417030383, 598631904, 849684835 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A219852

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = (1/39916800)*n^11 + (1/1209600)*n^10 + (1/120960)*n^9 + (1/10080)*n^8 + (1481/1209600)*n^7 + (131/19200)*n^6 + (14807/181440)*n^5 - (49747/120960)*n^4 + (78101/16800)*n^3 - (136007/16800)*n^2 + (44059/9240)*n + 2 for n>3

EXAMPLE

Some solutions for n=3

..2..0..0....2..1..1....1..0..0....0..0..0....1..0..0....1..0..0....0..0..0

..2..0..1....2..1..2....1..0..1....0..0..0....1..0..0....1..0..1....0..0..0

..2..1..2....2..2..2....1..2..2....0..0..2....2..0..2....1..1..1....0..0..1

CROSSREFS

Sequence in context: A195741 A006758 A123189 * A047156 A128243 A219294

Adjacent sequences:  A219844 A219845 A219846 * A219848 A219849 A219850

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 29 2012

STATUS

approved

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Last modified April 5 00:43 EDT 2020. Contains 333238 sequences. (Running on oeis4.)