若数列{an}满足a1+3a2+3^2a3+……+3^(n-1)an=(n+1)/3,则求an

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 (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{an}满足a1=1,an=a1+1/2a2+1/3a3+…+1/(n-1)a(n-1),若an=2006,则n=___为什么a1=a2=1先求通项公式 若数列an满足,a1+a2+a3+.+an=3n-2求 an的通项公式 设数列{an}满足：a1+a2/2+a3/3+a4/4……+an/n=An+B,其中A、B为常数.数列{an}是否为等差数列? 已知两个等比数列｛an｝,｛bn｝,满足a1=a（a＞0）,b1-a1=1,b2-a2=2,b3-a3=3,若数列｛an｝唯一,求若数列｛an｝唯一,求a的值 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,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=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+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 若数列｛an｝满足：a1=1,an+1=2an,n=1,2,3….则a1+a2+…+an=______. 若数列｛an｝满足a1=1,an+1=2an,n=1,2,3,……,则a1+a2+……+an=____________ 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=a,an+1=1+1/an.若3/2 若数列{an}满足a1+2a2+3a3+~~+nan=n(n+1)(2n+1),则an= 已知数列{an}满足a1=1,a2=3,an+2=3an+1-2an求an