

A198178


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


0




OFFSET

1,2


COMMENTS

Every 0 is next to 0 0'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
Diagonal of A198185


LINKS

Table of n, a(n) for n=1..9.


EXAMPLE

Some solutions for n=4
..0..2..1..1....0..3..0..1....1..0..3..0....1..0..2..1....1..0..1..2
..1..1..0..2....1..0..3..2....2..3..0..1....2..1..1..0....2..1..0..1
..2..0..1..1....2..1..0..1....1..0..1..2....2..1..0..1....0..1..1..0
..1..1..2..0....0..1..2..1....1..2..1..0....1..0..1..2....1..2..2..1


CROSSREFS

Sequence in context: A197859 A197997 A309444 * A013571 A002942 A028908
Adjacent sequences: A198175 A198176 A198177 * A198179 A198180 A198181


KEYWORD

nonn


AUTHOR

R. H. Hardin Oct 21 2011


STATUS

approved



