A205304 Number of n X n 0..3 arrays with no occurrence of three equal elements in a row horizontally or vertically, and new values 0..3 introduced in row major order.

1, 15, 7445, 70985206, 8615950028840, 13585407518869992739

Offset: 1

Author

R. H. Hardin, Jan 25 2012

Keywords

• nonn

Examples

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

Crossrefs

Diagonal of A205310.