A208868 Number of nX4 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.

15, 1798, 307165, 52947540, 9130195864, 1574432811027, 271499374919883, 46818078167209471, 8073434644321782464, 1392204668383719239473, 240075497495975972163390, 41399261047580372916745574

Offset: 1

Author

R. H. Hardin Mar 02 2012

Keywords

• nonn

Comments

Column 4 of A208872

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 198*a(n-1) -4637*a(n-2) +40574*a(n-3) -164314*a(n-4) +321776*a(n-5) -281785*a(n-6) +85300*a(n-7) -8100*a(n-8) for n>9