A215921 Number of diagonal and antidiagonal neighbor colorings of the odd squares of an n X 3 array with new integer colors introduced in row major order.

1, 2, 4, 42, 136, 2906, 12840, 433252, 2387180, 113503692, 742181112, 46538017584, 350038464728, 27700815674032, 234578644301776, 22702140562948192, 213078984368820288, 24626774613248937584, 253140626416265149920

Offset: 1

Author

R. H. Hardin Aug 27 2012

Keywords

• nonn

Comments

Column 3 of A215924.

Examples

			Some solutions for n=4
..x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x
..1..x..2....1..x..1....1..x..2....1..x..1....1..x..2....1..x..2....1..x..1
..x..3..x....x..2..x....x..0..x....x..2..x....x..0..x....x..3..x....x..2..x
..1..x..1....3..x..1....3..x..4....1..x..1....2..x..2....4..x..5....0..x..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..98

Crossrefs

Cf. A215924.