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A183451
Number of n X n binary arrays with every 1 having exactly three king-move neighbors equal to 1.
0
1, 2, 5, 10, 60, 439, 2906, 36995, 739752, 16870217, 577680500, 39980454239, 4671945102210
OFFSET
1,2
COMMENTS
Diagonal of A183456.
EXAMPLE
Some solutions for 5X5
..1..1..0..1..1....0..0..0..0..0....1..1..0..0..0....0..0..0..1..1
..1..1..0..1..1....1..1..0..0..0....1..1..0..1..1....0..0..0..1..1
..0..0..0..0..0....1..1..0..0..0....0..0..0..1..1....0..0..0..0..0
..0..1..1..0..0....0..0..0..1..1....0..0..0..0..0....0..1..1..0..0
..0..1..1..0..0....0..0..0..1..1....0..0..0..0..0....0..1..1..0..0
CROSSREFS
Sequence in context: A018503 A018535 A140304 * A018549 A053356 A018584
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2011
STATUS
approved