A208045 Number of n X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any horizontal, vertical or antidiagonal neighbor (colorings ignoring permutations of colors).

1, 2, 44, 1904, 168096, 30818432, 11838995200, 9578237457408, 16372889877477376, 59262411624914853888, 454901302416508366209024, 7413673375795915677473636352

Offset: 1

Author

R. H. Hardin Feb 22 2012

Keywords

• nonn

Comments

Diagonal of A208050

Examples

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

Programs

Mathematica

A208050 = Cases[Import["https://oeis.org/A208050/b208050.txt", "Table"], {, }][[All, 2]];
a[n_] := A208050[[2 n^2 - 2 n + 1]];
Table[a[n], {n, 1, 12}] (* Jean-François Alcover, Sep 23 2019 *)