A224305 Number of n X 3 0..2 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.

22, 218, 1586, 11361, 82700, 615481, 4634768, 35003328, 264487714, 1997888432, 15087449584, 113921725004, 860155842566, 6494472790364, 49035576285772, 370236844834368, 2795429838028120, 21106576528056696, 159362840727871756

Offset

1,1

Comments

Column 3 of A224310.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -16*a(n-2) -24*a(n-3) -44*a(n-4) +728*a(n-5) -678*a(n-6) -722*a(n-7) -860*a(n-8) +9336*a(n-9) -3916*a(n-10) +792*a(n-11) +320*a(n-12) -11936*a(n-13) +2848*a(n-14) +128*a(n-15) +384*a(n-16) +3840*a(n-17).

Example

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

Crossrefs

Cf. A224310.

Sequence in context: A224330 A223928 A224052 * A224369 A331882 A008453

Adjacent sequences: A224302 A224303 A224304 * A224306 A224307 A224308

Keyword

nonn

Author

R. H. Hardin Apr 03 2013

Status

approved