A201698 Number of nX6 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards

3, 48, 2068, 167625, 14268351, 795339012, 27102769900, 615440785548, 10106227864338, 127441635892627, 1290114077123683, 10846768837607450, 77797729805055016, 486398599750167133, 2697872438447793007

Offset

1,1

Comments

Column 6 of A201700

Links

R. H. Hardin, Table of n, a(n) for n = 1..90

Formula

Empirical: a(n) is a polynomial of degree 34

Example

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

Crossrefs

Sequence in context: A304208 A300871 A341498 * A356612 A295813 A326217

Adjacent sequences: A201695 A201696 A201697 * A201699 A201700 A201701

Keyword

nonn

Author

R. H. Hardin Dec 03 2011

Status

approved