A207980 Number of n X 4 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).

15, 1080, 587208, 953124784, 3410310590912, 22727131144960768, 253335104721267417984, 4382417290595586402531584, 111319355727036703898865465344, 3978834602846298450265688566196224, 193442461762324413798952526604793292800

Offset: 1

Author

R. H. Hardin, Feb 22 2012

Keywords

• nonn

Examples

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

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..140

Crossrefs

Column 4 of A207981.

Extensions

Terms a(8) and beyond from Andrew Howroyd, Mar 15 2023