已知函数,数列{an}满足a1=1,an+1=f(an)(n∈N+),(1)求数列{an}的通项公式an;(2)若数列{bn}满足bn=anan+1·3n,Sn=b1+b2+…+bn,求Sn。-高三数

题目简介

已知函数,数列{an}满足a1=1,an+1=f(an)(n∈N+),(1)求数列{an}的通项公式an;(2)若数列{bn}满足bn=anan+1·3n,Sn=b1+b2+…+bn,求Sn。-高三数

题目详情

已知函数,数列{an}满足a1=1,an+1=f(an)(n∈N+),
(1)求数列{an}的通项公式an
(2)若数列{bn}满足bn=anan+1·3n,Sn=b1+b2+…+bn,求Sn
题型:解答题难度:中档来源:广东省月考题

答案

解:(1)由已知:


∴数列为首项,3为公比的等比数列,


(2)

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