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PUMaC 2008 · 组合（B 组） · 第 5 题

PUMaC 2008 — Combinatorics (Division B) — Problem 5

专题
Discrete Math / 离散数学
难度
L3
来源
PUMaC

题目详情

  1. (4 points) Evaluate ( )( ) 2009 m ∑ ∑ 2009 m . m n m =0 n =0
解析
  1. Evaluate ( )( ) 2009 m ∑ ∑ 2009 m . m n m =0 n =0 2009 ( ANS: 3 . ( )( ) ( ) ( ) ( ) 2009 m 2009 m 2009 ∑ ∑ ∑ ∑ ∑ 2009 m 2009 m 2009 m 2009 2009 = = (1 + 1) = (1 + 1 + 1) = 3 m n m n m m =0 n =0 m =0 n =0 m =0 CB: GL)