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A067211
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Number of n X n 0..3 matrices with all row and column sums equal.
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1
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4, 16, 340, 89520, 290838284, 12092687195284, 6675338514190905402, 50327836869668591230004816, 5292118931181847999077738163123240, 7888144623867099277720906683959732404332016, 168815361056027801755263418243053345902341535059333028
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OFFSET
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1,1
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LINKS
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EXAMPLE
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Some solutions for n=3
..2..1..1....1..3..1....0..2..1....2..2..2....0..0..3....1..2..1....1..3..3
..0..1..3....1..1..3....3..0..0....2..2..2....2..1..0....0..1..3....3..1..3
..2..2..0....3..1..1....0..1..2....2..2..2....1..2..0....3..1..0....3..3..1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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