login
A197301
Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,4,0,2,1 for x=0,1,2,3,4
0
1, 7, 31, 639, 27709, 2533633, 638181656, 388800452625, 561392899488562
OFFSET
1,2
COMMENTS
Every 0 is next to 0 4's, every 1 is next to 1 4's, every 2 is next to 2 0's, every 3 is next to 3 2's, every 4 is next to 4 1's
Diagonal of A197307
EXAMPLE
Some solutions for n=4
..0..2..0..2....0..0..1..0....2..0..2..0....0..2..0..2....2..0..0..0
..2..3..2..0....0..1..4..1....0..0..3..2....0..3..2..0....0..2..2..0
..0..0..2..0....0..2..1..0....0..2..2..0....0..2..2..0....0..2..3..0
..0..0..2..0....2..0..2..0....0..2..0..0....2..0..0..2....0..0..2..0
CROSSREFS
Sequence in context: A139307 A197451 A289729 * A280038 A253640 A191297
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 13 2011
STATUS
approved