[分析] 歸納法證明

[u2150260 (鴻哥)]

Prove that (2n)!/((n!)^2) 小於等於 4^(n-1) for all positive integers
  n大於等於5

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◆ From: 122.116.6.196
→ doom8199:set n=k is true:  C(2k,k) <= 4^(k-1)
→ doom8199:then n=k+1 : C(2k+2,k+1)=C(2k,k+1)+2C(2k,k)+C(2k,k-1)
→ doom8199:<= 4C(2k,k) = 4*4^(k-1)