A208347 Number of nX2 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors).

2, 15, 100, 868, 7780, 69988, 629860, 5668708, 51018340, 459165028, 4132485220, 37192366948, 334731302500, 3012581722468, 27113235502180, 244019119519588, 2196172075676260, 19765548681086308, 177889938129776740

Offset: 1

Author

R. H. Hardin Feb 25 2012

Keywords

• nonn

Comments

Column 2 of A208353

Examples

			Some solutions for n=4
..0..0....0..1....0..0....0..0....0..0....0..0....0..1....0..0....0..0....0..0
..0..0....1..0....0..0....0..0....1..0....1..1....1..2....0..0....0..0....1..0
..1..1....0..1....1..2....1..1....1..1....1..1....0..1....1..1....1..2....1..1
..2..2....1..2....3..2....1..1....1..0....0..0....0..0....1..2....1..3....1..2
		

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -9*a(n-2) for n>4