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A225989
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Number of pairs of orthogonal (-1,3) vectors of length 4*n.
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1
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20, 3192, 652784, 134432480, 28244153600, 6052498776192, 1314942362273280, 288501497813552640, 63776322167821168640, 14182989297327325110272, 3169467786802943379238912, 711136363409644515952173056
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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 solutions for n=1
.-1..3...-1..3....3..3...-1..3...-1..3...-1..3...-1..3...-1.-1....3..3...-1..3
..3..3...-1..3...-1..3....3..3...-1..3....3.-1...-1..3...-1.-1...-1..3....3.-1
.-1..3....3..3...-1..3....3.-1....3.-1....3..3...-1..3...-1.-1....3.-1....3..3
..3.-1....3.-1....3.-1...-1..3....3..3...-1..3....3..3...-1..3....3.-1....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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STATUS
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approved
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