A231024 Number of n X n 0..2 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero

0, 2, 60, 43566, 124446770, 2846678305070, 441589771066454894, 487992556962953668919304

Offset

1,2

Comments

Diagonal of A231031

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Sequence in context: A173221 A082787 A078423 * A356584 A121493 A078491

Adjacent sequences: A231021 A231022 A231023 * A231025 A231026 A231027

Keyword

nonn

Author

R. H. Hardin, Nov 03 2013

Status

approved