

A197173


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


0




OFFSET

1,2


COMMENTS

Every 0 is next to 0 2's, every 1 is next to 1 2'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 containing all values 0 to 4 for n=4
..0..0..1..2....0..1..2..1....1..2..1..0....0..0..0..0....0..0..1..2
..0..4..0..1....3..0..3..0....0..3..0..0....0..4..0..0....3..0..0..1
..0..0..4..0....0..4..0..1....3..0..4..0....3..0..0..1....0..4..0..0
..0..3..0..0....0..0..1..2....0..0..0..0....0..0..1..2....0..0..0..0


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



