A215953 Number of horizontal, vertical and diagonal neighbor colorings of the even squares of an n X 2 array with new integer colors introduced in row major order.

1, 1, 2, 4, 12, 34, 136, 500, 2440, 10900, 61912, 322768, 2075312, 12297768, 87852160, 580849872, 4548247264, 33093252880, 281121815712, 2227152575552, 20358402201792, 174131286983712, 1701534399324544, 15604440074084672

Offset: 1

Author

R. H. Hardin, Aug 28 2012

Keywords

• nonn

Comments

Column 2 of A215959.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..122