A219910 Number of nX3 arrays of the minimum value of corresponding elements and their horizontal, vertical, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX3 array

6, 6, 24, 62, 155, 356, 789, 1716, 3676, 7708, 15724, 31125, 59808, 111782, 203708, 362808, 632759, 1082409, 1818433, 3003399, 4881149, 7811931, 12320359, 19160044, 29399646, 44536162, 66642506, 98557873, 144131030, 208528564, 298622262

Offset

1,1

Comments

Column 3 of A219915

Links

R. H. Hardin, Table of n, a(n) for n = 1..196

Formula

Empirical: a(n) = (1/39916800)*n^11 - (1/907200)*n^10 + (5/145152)*n^9 - (17/30240)*n^8 + (659/134400)*n^7 + (587/43200)*n^6 - (80861/145152)*n^5 + (10118/2835)*n^4 + (994429/907200)*n^3 - (1059433/12600)*n^2 + (417125/1386)*n - 304 for n>6

Example

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

Crossrefs

Sequence in context: A306896 A087236 A341267 * A334569 A077193 A056482

Adjacent sequences: A219907 A219908 A219909 * A219911 A219912 A219913

Keyword

nonn

Author

R. H. Hardin Dec 01 2012

Status

approved