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A159718
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Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 4 local maxima.
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2
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0, 0, 0, 88, 33600, 3821760, 272509552, 15313310208, 750469872312, 33813251867920, 1443455210369040, 59454199364673024, 2389923754993613176, 94450458835284703536, 3687585353084799432720, 142691482885508987276800, 5484263653598164634676600, 209677462059979688650122960
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OFFSET
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1,4
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LINKS
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PROG
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(PARI) \\ CircPeaksBySig defined in A334778.
a(n) = {CircPeaksBySig(vector(n, i, 2), [4])[1]} \\ Andrew Howroyd, May 13 2020
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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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