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A019577
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Place n distinguishable balls in n boxes (in n^n ways); let f(n,k) = number of ways that max in any box is k, for 1<=k<=n; sequence gives f(n,2)/n.
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1
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0, 1, 6, 45, 420, 4800, 65520, 1045170, 19126800, 395448480, 9120988800, 232248416400, 6471820555200, 195912193276800, 6402199349145600, 224636583525354000, 8423131243022496000, 336138596955120960000, 14224375944427993344000, 636224790017466730080000
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OFFSET
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1,3
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LINKS
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FORMULA
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Sum n! (n-1)! / ( 2^d (n-2d)! d! d! ), d=1..[ n/2 ].
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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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STATUS
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approved
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