

A197310


Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 0,1,1,0,0 for x=0,1,2,3,4


0




OFFSET

1,3


COMMENTS

Every 0 is next to 0 0's, every 1 is next to 1 1's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's


LINKS



EXAMPLE

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


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



