A183361 One quarter the number of nX9 1..4 arrays with no two neighbors of any element equal to each other.

8748, 589824, 314928, 435600, 802944, 1679616, 3852288, 9437184, 23003136, 47775744, 95551488, 191102976, 389283840, 807469056, 1695744000, 3588489216, 7596343296, 16057958400, 33888927744, 71430045696, 150473539584

Offset: 1

Author

R. H. Hardin Jan 04 2011

Keywords

• nonn

Comments

Column 9 of A183362

Examples

			Some solutions for 5X9 with a(1,1)=1
..1..1..2..3..3..1..2..3..4....1..1..2..4..4..2..2..3..1
..2..4..4..1..2..4..4..1..1....2..4..3..3..1..1..4..3..2
..2..3..3..1..2..3..3..2..2....2..4..1..2..2..3..4..1..2
..4..1..2..4..4..1..1..4..3....3..3..1..4..4..3..2..1..3
..3..1..2..3..3..2..2..4..1....4..2..2..3..1..1..2..4..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..26