A215900 Number of diagonal and antidiagonal neighbor colorings of the even squares of an nX3 array with new integer colors introduced in row major order.

2, 2, 15, 42, 726, 2906, 84550, 433252, 18378580, 113503692, 6485270720, 46538017584, 3404551437592, 27700815674032, 2504332323669064, 22702140562948192, 2470653950084307472, 24626774613248937584

Offset: 1

Author

R. H. Hardin Aug 26 2012

Keywords

• nonn

Comments

Column 3 of A215904

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..96