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A233019
Number of n X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero
1
1, 15, 849, 179999, 149128385, 487651369463, 6338787392715565, 328918675019714663095, 68332288847776936953486283, 56955693489584720827393016043135
OFFSET
1,2
COMMENTS
Diagonal of A233026
LINKS
EXAMPLE
Some solutions for n=4
..0..0..2..3....0..0..2..3....0..0..2..2....0..2..2..0....0..2..0..0
..0..2..2..2....2..0..2..2....2..0..0..2....0..2..0..2....2..0..2..2
..0..2..3..3....2..2..0..2....0..0..0..0....0..2..2..2....0..2..0..2
..0..2..2..3....0..0..2..2....0..0..0..0....0..2..0..2....2..2..0..0
CROSSREFS
Sequence in context: A020240 A281695 A223276 * A270962 A223818 A208349
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 03 2013
STATUS
approved