A198907 Number of n X n 0..7 arrays with values 0..7 introduced in row major order and no element equal to any horizontal or vertical neighbor.

1, 4, 2051, 319608038, 4717456775959530, 2869765342757082981876352

Offset: 1

Author

R. H. Hardin Oct 31 2011

Keywords

• nonn

Comments

Diagonal of A198914

Examples

			Some solutions with values 0 to 7 for n=3
..0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2
..3..4..5....3..4..5....3..4..5....3..4..1....3..4..5....3..4..5....3..4..5
..6..7..4....1..6..7....4..6..7....5..6..7....2..6..7....6..0..7....6..2..7
		

Links

• Jean-François Alcover, Table of n, a(n) for n = 1..12

Programs

Mathematica

A198914 = Cases[Import["https://oeis.org/A198914/b198914.txt", "Table"], {, }][[All, 2]];
a[n_] := A198914[[2 n^2 - 2 n + 1]];
Table[a[n], {n, 1, 12}] (* Jean-François Alcover, Sep 23 2019 *)