A216457 Number of horizontal, diagonal and antidiagonal neighbor colorings of the even squares of an nX3 array with new integer colors introduced in row major order.

1, 1, 7, 20, 322, 1335, 36401, 192713, 7712455, 49055292, 2659544320, 19602119017, 1367160898137, 11399696350555, 986429423363481, 9146845346099410, 955922762706415420, 9731199828137067515, 1203020866861467699281

Offset: 1

Author

R. H. Hardin Sep 07 2012

Keywords

• nonn

Comments

Column 3 of A216460

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..95