A207993 Number of n X n 0..2 arrays with new values 0..2 introduced in row major order and no element equal to any horizontal or vertical neighbor (colorings ignoring permutations of colors).

1, 3, 41, 1302, 96831, 16932816, 6978332618, 6787438272198, 15595829208171337, 84713253582265127190, 1088296274542436098185362, 33079232010276428576508643620, 2379573338713223879592059518246838

Offset

1,2

Comments

Diagonal of A207997.

Links

R. H. Hardin, Table of n, a(n) for n = 1..16

Example

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

Mathematica

A207997 = Import["https://oeis.org/A207997/b207997.txt", "Table"][[All, 2]];
a[n_] := A207997[[2 n^2 - 2 n + 1]];
Table[a[n], {n, 1, 16}] (* Jean-François Alcover, Sep 23 2019 *)

Crossrefs

Sequence in context: A012129 A012035 A012016 * A187540 A012104 A012147

Adjacent sequences: A207990 A207991 A207992 * A207994 A207995 A207996

Keyword

nonn

Author

R. H. Hardin, Feb 22 2012

Status

approved