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A188350
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Number of arrangements of n+1 numbers x(i) in -1..1 with the sum of x(i)*x(i+1) equal to zero
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1
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5, 15, 29, 91, 197, 627, 1477, 4671, 11693, 36487, 95405, 293695, 792525, 2412175, 6660989, 20097243, 56450693, 169229571, 481426405, 1436666475, 4126292293, 12275100443, 35511918037, 105423983379, 306684489749, 909271908483
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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=4
..1....0....1...-1....0...-1....1....0....1...-1....0....0...-1...-1...-1....0
..0....0....0....0....0...-1....0....1....1....0....0....0....1....0....0....0
.-1...-1....1....1...-1....1...-1...-1....0...-1...-1...-1....1....0....0....1
.-1....0....0...-1....0....0....0...-1...-1....1....0...-1....0....0...-1....1
..1....1...-1...-1...-1....1...-1....0....1....1....0....1...-1...-1....0...-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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