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

1,2

Comments

Diagonal of A198914

Links

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

Example

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

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 *)

Crossrefs

Sequence in context: A198716 A365369 A004815 * A207863 A220941 A012869

Adjacent sequences: A198904 A198905 A198906 * A198908 A198909 A198910

Keyword

nonn

Author

R. H. Hardin Oct 31 2011

Status

approved