已知等差数列{a n }的首项a 1 =1,公差d>0,且a 2 ,a 5 ,a 14 恰好是等比数列{b n }的前3项. (Ⅰ)求数列{a n }与{b n }的通项公式; (Ⅱ)若数列{c n }对于任意自然数n均有 1 c n =( a n +3)?lo g 3 b n ,求数列{c n }的前n项和.
【简答题】听力原文:A briefcase containing over $ 10,000 in cash was found on a United Airlines flight that arrived in New York on Tuesday night. The bag is believed to belong to a passenger. So far, no one has cont...