来自钱九阳的问题
【设数列{an}满足a1=2,an+1=an+3•2n-1.(1)求数列{an}的通项公式an;(2)令bn=nan,求数列{bn}的前n项和Sn;(3)令cn=log2an+13,证明:1c2c3+1c3c4+…+1cncn+1<1(n≥2).】
设数列{an}满足a1=2,an+1=an+3•2n-1.
(1)求数列{an}的通项公式an;
(2)令bn=nan,求数列{bn}的前n项和Sn;
(3)令cn=log2an+13,证明:1c2c3+1c3c4+…+1cncn+1<1(n≥2).
1回答
2020-02-1407:20