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A187671
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Number of 3X3 0..n arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal
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1
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24, 550, 4044, 17716, 56080, 150166, 336776, 702408, 1330728, 2385910, 3973400, 6550700, 10068336, 15247986, 22545648, 32579360, 45246528, 62983046, 84524916, 113900920, 150370548, 195521534, 249456396, 321513812, 404142192, 504603526
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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Some n=3 solutions for 3X3
..3..3..3....2..1..3....0..1..0....2..1..1....1..0..3....3..0..2....2..3..1
..0..1..0....2..0..2....2..1..2....2..2..0....0..3..2....0..1..2....1..0..1
..3..0..3....0..1..0....2..2..2....2..1..1....3..3..3....2..0..3....2..3..2
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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