A224007 Number of n X 3 0..2 arrays with rows nondecreasing and antidiagonals unimodal.

10, 100, 868, 7378, 62764, 534352, 4549684, 38737252, 329817976, 2808146488, 23909211472, 203568584872, 1733230255168, 14757125302768, 125645595288400, 1069775806044208, 9108319894356832, 77550352914336256, 660281732184575104

Offset

1,1

Comments

Column 3 of A224012.

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) + 30*a(n-3) - 14*a(n-4) + 12*a(n-5).

Empirical g.f.: 2*x*(5 + 14*x^2 - x^3 + 6*x^4) / (1 - 10*x + 16*x^2 - 30*x^3 + 14*x^4 - 12*x^5). - Colin Barker, Aug 26 2018

Example

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

Crossrefs

Cf. A224012.

Sequence in context: A218269 A224348 A213298 * A136876 A231157 A231163

Adjacent sequences: A224004 A224005 A224006 * A224008 A224009 A224010

Keyword

nonn

Author

R. H. Hardin, Mar 30 2013

Status

approved