A230063 Number of nX3 0..2 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value 2-x(i,j)

0, 9, 45, 441, 3645, 31329, 266805, 2277081, 19424205, 165714129, 1413721125, 12060652041, 102890947005, 877775988609, 7488419962005, 63884675998521, 545008403548845, 4649536929125169, 39665798745571845, 338394040998364521

Offset

1,2

Comments

Column 3 of A230068

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +14*a(n-2) -8*a(n-3).

Empirical: G.f.: -9*x^2*(-1+2*x) / ( (2*x+1)*(4*x^2-9*x+1) ). - R. J. Mathar, Mar 21 2016

Example

Some solutions for n=4
..0..1..0....2..0..2....1..2..1....0..2..0....0..1..0....0..0..0....0..2..0
..1..2..0....2..0..2....0..1..0....2..2..0....1..2..1....2..2..2....0..2..0
..0..2..1....2..2..2....0..1..0....0..0..0....1..2..0....1..2..0....2..2..0
..0..1..0....0..0..0....1..2..1....2..2..2....0..1..0....0..1..0....0..0..0

Crossrefs

Sequence in context: A290358 A030113 A001556 * A009432 A145757 A058824

Adjacent sequences: A230060 A230061 A230062 * A230064 A230065 A230066

Keyword

nonn

Author

R. H. Hardin, Oct 08 2013

Status

approved