A199252 Number of nX4 0..3 arrays with values 0..3 introduced in row major order, the number of instances of each value within one of each other, and no element equal to any horizontal or vertical neighbor.

1, 21, 447, 11223, 305863, 8862785, 267827143, 8351549833, 266729329121, 8681405364211, 286916350055011, 9603063714049169, 324843085529291745, 11088239688730868231, 381446891741918303003, 13211448568439934521121

Offset: 1

Author

R. H. Hardin Nov 04 2011

Keywords

• nonn

Comments

Column 4 of A199256

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..19