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18.03.2013

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, k k!

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(n + 1)(n + 2)...(n + k) / k! = 1 2 ... n (n + 1)(n + 2)...(n + k) / [k! n!] =

= (n + k)! / [k! n!] = (n + k)! / [k! (n + k - k)!]. , Ckn + k, .


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