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A226283
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[n/2]!*[(n+1)/2]!*C([n/2],2)*C([(n+1)/2],2).
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3
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0, 0, 0, 4, 36, 324, 2592, 20736, 172800, 1440000, 12960000, 116640000, 1143072000, 11202105600, 119489126400, 1274550681600, 14748372172800, 170659735142400, 2133246689280000, 26665583616000000, 358503957504000000
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OFFSET
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1,4
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COMMENTS
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Number of permutations of n elements with 4 odd displacements.
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LINKS
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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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