A217267 Number of n X n arrays of occupancy after each element moves to some horizontal or vertical neighbor.

0, 9, 1472, 2572816, 48909857500, 10211121295308649, 23397344246732649325860

Offset: 1

Author

R. H. Hardin, Sep 29 2012

Keywords

• nonn
• hard
• more

Examples

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

Crossrefs

Diagonal of A217273.