A229588 Number of defective 3-colorings of a 3 X n 0..2 array connected horizontally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.

0, 40, 264, 1620, 9156, 49848, 264300, 1374048, 7036116, 35600376, 178380156, 886616784, 4377006372, 21483378600, 104919416268, 510169843584, 2471194910580, 11929478452824, 57413851328028, 275566856985648

Offset: 1

Author

R. H. Hardin, Sep 26 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Row 3 of A229586.

Formula

Empirical: a(n) = 10*a(n-1) - 29*a(n-2) + 20*a(n-3) - 4*a(n-4) for n>6.

Empirical g.f.: 4*x^2*(10 - 34*x + 35*x^2 - 47*x^3 + 37*x^4) / (1 - 5*x + 2*x^2)^2. - Colin Barker, Sep 19 2018