A229454 - OEIS

A229454

Number of defective 3-colorings of an n X 3 0..2 array connected horizontally and vertically with exactly one mistake and colors introduced in row-major 0..2 order.

2, 20, 140, 863, 4962, 27313, 145932, 763031, 3924694, 19928429, 100145056, 498967875, 2468341930, 12136538329, 59362244596, 289033801519, 1401690320766, 6773621702213, 32630424771912, 156746889564187, 751052250017618

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) - 29*a(n-2) + 20*a(n-3) - 4*a(n-4).

Empirical g.f.: x*(2 - 2*x^2 + 3*x^3) / (1 - 5*x + 2*x^2)^2. - Colin Barker, Sep 17 2018

EXAMPLE

Some solutions for n=3:

..0..0..1....0..1..0....0..1..2....0..1..0....0..1..2....0..1..2....0..1..0

..2..1..0....0..2..1....2..0..1....1..0..1....1..2..1....2..2..0....2..1..2

..1..0..2....2..1..0....1..2..1....0..2..2....2..0..0....1..0..2....1..0..1

CROSSREFS

Column 3 of A229460.

Sequence in context: A093647 A244887 A279112 * A003490 A081006 A003481

Adjacent sequences: A229451 A229452 A229453 * A229455 A229456 A229457

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 24 2013

STATUS

approved