A230657 - OEIS

A230657

Number of n X n 0..2 black square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value 2-x(i,j)

1, 3, 15, 123, 8613, 337977, 169006665, 40860127671, 131515599970167, 201844710508818147, 4141132208926170478473, 40464088148356899296269059

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Diagonal of A230661

LINKS

EXAMPLE

Some solutions for n=5

..x..1..x..1..x....x..2..x..0..x....x..1..x..1..x....x..1..x..1..x

..1..x..1..x..1....0..x..1..x..2....1..x..0..x..1....1..x..2..x..1

..x..2..x..2..x....x..1..x..0..x....x..2..x..1..x....x..0..x..0..x

..0..x..1..x..0....2..x..2..x..1....2..x..1..x..2....2..x..0..x..2

..x..2..x..1..x....x..0..x..1..x....x..0..x..0..x....x..2..x..0..x

CROSSREFS

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 27 2013

STATUS

approved