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A154656
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Number of permutations of length n within distance 7.
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6
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1, 1, 2, 6, 24, 120, 720, 5040, 40320, 287280, 1865520, 11345160, 66349464, 381523758, 2193664790, 12764590275, 75796724309, 455383613924, 2750869551868, 16635586999056, 100439873614656, 604666567043712, 3629299734118656, 21736009354060800, 130082373922081536
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OFFSET
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0,3
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COMMENTS
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a(n) equals the permanent of the n X n matrix with 1's along the central fifteen diagonals, and 0's everywhere else. - John M. Campbell, Jul 10 2011
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LINKS
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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