数列An满足：A1=1,A2=2/3,An+2=3/2An+1-1/2An,记dn=An+1-An,求证dn是等比数列（2）求数列An的通项公式（3）令Bn=3n-2,求数列An*Bn的前n项和Sn

数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an (1)数列{an}中,a1=1,a2=-3,a(n+1)=an+a(n+2),则a2005=____(2)已知数列｛an｝满足a1=1,a1×a2×a3…an=n^2,求an. 已知数列{an}满足a1=1,a2=3,a(n+2)=a(n+1)-an,求S2012 已知数列满足a1=1/2,an+1=2an/(an+1),求a1,a2已知数列满足a1=1/2,a(n+1)=2an/(an+1),求a1,a2;证明0 设数列AN满足A1等于1,3(A1+a2+~+AN)=(n+2)an,求通向公式 数列an满足a1=2,a2=5,a(n+2)=3a(n+1)-2an,求数列{an}的通项公式 已知数列{an}满足a1=1,a2=3,an+2=3an+1-2an求an 已知数列{an}满足a1=4/3,2-a(n+1)=12/an+6则1/a1+2/a2+.1/an=? 已知数列{an}满足：a1=1,an=a1+2a2+3a3+``````+(n-1)a(n-1)(n大于等于2）,则通项公式an是什么? 已知数列an满足a1=1,an=a1+2a2+3a3+4a4+.(n-1)a(n-1),求通项an 数列{An}满足A1+3A2+3^2*A3+.+3^N-1*An=n/3 A属于N紧急求数列{An}的通项 已知数列{an}中满足a1=1,a(n+1)=2an+1 (n∈N*),证明a1/a2+a2/a3+…+an/a(n+1) 数列{an}满足a1=3,a2=6,an+2=an+1-an,求a2013 数列{an}满足a1=3,a2=6,an+2=an+1-an,求a2008 已知数列｛an｝的前n项和为Sn 1若数列｛an｝是等比数列,满足2a1+a3=3a2.a3+2是a已知数列｛an｝的前n项和为Sn1若数列｛an｝是等比数列,满足2a1+a3=3a2.a3+2是a2.a4的等差中项,求数列｛an｝的通向公式 已知数列{an}满足条件:a1=5,an=a1+a2+...a(n-1) n大于等于2,求数列{an}的通项公式 已知数列an满足an=1+2+...+n,且1/a1+1/a2+...+1/an 已知数列{an}满足a1=a,a2=b,a(n+1)=a(n+2)+an,求a2012