A208194 Number of n X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or left-upward diagonal neighbors.

1, 14, 10366, 156617480, 37069738362057, 136398703432330477549, 7801822458198433796561428608, 6937084083184530563330081968289999750, 95885498147917477608538934758547979039384601906

Offset: 1

Author

R. H. Hardin Feb 24 2012

Keywords

• nonn

Comments

Diagonal of A208201

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..10