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A209504
Half the number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock having two or four distinct clockwise edge differences
1
9, 123, 3906, 290493, 50798448, 20934997854, 20362314816594, 46787487624514011, 254139760746795381570, 3264888823627308294556086, 99237696030829285729525930860, 7138720016139671638776178554740514
OFFSET
1,1
COMMENTS
Diagonal of A209511
LINKS
EXAMPLE
Some solutions for n=4
..1..2..0..2..0....2..0..1..2..0....0..1..0..1..0....0..1..2..0..1
..2..1..2..1..2....0..2..0..1..2....1..2..1..2..1....1..2..0..1..2
..0..2..1..2..1....2..0..1..2..0....2..1..2..1..2....2..1..2..0..1
..1..0..2..1..2....0..2..0..1..2....1..0..1..2..0....1..0..1..2..0
..0..1..0..2..1....1..0..1..2..0....2..1..2..1..2....0..2..0..1..2
CROSSREFS
Sequence in context: A295549 A211101 A269627 * A320529 A280896 A364940
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 09 2012
STATUS
approved