A219878 Number of nX3 arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX3 array

6, 11, 47, 146, 410, 1069, 2701, 6645, 15787, 36047, 79071, 166909, 339837, 668982, 1276058, 2363344, 4258060, 7476554, 12815234, 21476998, 35244068, 56710659, 89591851, 139128423, 212611297, 320053673, 475043961, 695818283, 1006597679

Offset

1,1

Comments

Column 3 of A219883

Links

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

Formula

Empirical: a(n) = (1/19958400)*n^11 + (1/907200)*n^10 - (1/72576)*n^9 + (29/120960)*n^8 + (31/28800)*n^7 - (263/10800)*n^6 + (175169/362880)*n^5 - (1469677/362880)*n^4 + (901433/56700)*n^3 + (759737/50400)*n^2 - (837073/3960)*n + 342 for n>4

Example

Some solutions for n=3
..1..0..0....2..0..0....0..0..0....1..0..0....2..1..1....1..0..0....1..0..1
..1..0..1....2..0..1....0..0..0....1..0..1....2..1..1....1..0..1....1..0..0
..1..2..1....2..1..2....1..0..0....2..1..1....2..1..2....2..2..2....1..0..0

Crossrefs

Sequence in context: A094555 A271056 A271255 * A270292 A270899 A270327

Adjacent sequences: A219875 A219876 A219877 * A219879 A219880 A219881

Keyword

nonn

Author

R. H. Hardin Nov 30 2012

Status

approved