A222833 Number of n X n 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order.

1, 7, 72, 600, 4032, 24576, 138240, 743424, 3833856, 19267584, 94371840, 454557696

Offset: 1

Author

R. H. Hardin Mar 06 2013

Keywords

• nonn

Comments

Diagonal of A222838

Examples

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