A223994 Number of nX3 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.

10, 76, 476, 2980, 18672, 117386, 739672, 4664776, 29428242, 185670484, 1171477424, 7391425016, 46636189140, 294251036912, 1856576835280, 11714070469768, 73909919072136, 466334575535548, 2942337620960936

Offset: 1

Author

R. H. Hardin Mar 30 2013

Keywords

• nonn

Comments

Column 3 of A223999

Examples

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

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -24*a(n-2) -2*a(n-3) +30*a(n-4) +96*a(n-5) -150*a(n-6) -108*a(n-7) +48*a(n-8) +270*a(n-9)