A230735 Number of (n+3)X(n+3) 0..2 black square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero

2, 66, 2106, 320970, 43853402, 36695929036, 26681634560690, 121531720205091748, 479398570293769095556, 11869733818244916838154264

Offset

1,1

Comments

Diagonal of A230739

Links

Table of n, a(n) for n=1..10.

Example

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

Crossrefs

Sequence in context: A069865 A218433 A092884 * A361884 A261784 A350730

Adjacent sequences: A230732 A230733 A230734 * A230736 A230737 A230738

Keyword

nonn

Author

R. H. Hardin, Oct 28 2013

Status

approved