A229506 Number of defective 3-colorings of an n X 4 0..2 array connected diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.

0, 288, 4032, 50112, 575424, 6298560, 66764736, 691581888, 7040530368, 70711413696, 702522486720, 6917780251584, 67615723104192, 656742815497152, 6344497107509184, 61004779879896000, 584181772129884096

Offset

1,2

Comments

Column 4 of A229510

Links

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

Formula

Empirical: a(n) = 18*a(n-1) - 81*a(n-2) for n>4.

Conjectures from Colin Barker, Jun 16 2017: (Start)

G.f.: 288*x^2*(1 - x)*(1 - 3*x) / (1 - 9*x)^2.

a(n) = 64*3^(2*n-5)*(8*n - 3) for n>2.

(End)

Example

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

Crossrefs

Sequence in context: A235552 A033692 A182026 * A332429 A232340 A290028

Adjacent sequences: A229503 A229504 A229505 * A229507 A229508 A229509

Keyword

nonn

Author

R. H. Hardin, Sep 25 2013

Status

approved