数列｛an｝满足a1=1,a2=3,an+2-4an+1+4an=0数列满足A1=1,A2=3.并且An+2-4An+1+4An=0.1、证明{An+1-2An}是等比数列

数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an 已知数列{an}满足a1=1,a2=3,an+2=3an+1-2an求an 设数列AN满足A1等于1,3(A1+a2+~+AN)=(n+2)an,求通向公式 已知数列an满足a1=1,a2=3,an+1.an-1=an,求a2013 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 数列an满足a1=1,a2=1/3,并且an(an-1+an+1)=2an+1an-1.则数列第2012项为? 已知数列an满足an=1+2+...+n,且1/a1+1/a2+...+1/an 设数列{an}满足lg(1+a1+a2+...+an)=n+1,求通项公式an 数列an满足a1=1/2,a1+a2+a3……an=n^2an,则an 数列an满足,a1=1/4,a2=3/4,an+1=2an-an-1(n≥2,n属于N*),数列bn满足b1 已知数列{an}满足a1=1 an+1=an/(3an+1) 则球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+a2+...+an=n²an求其通项an 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=____________ 已知,数列{an}满足a1=1,an+1=3an +1,证明:1/a1+1/a2+…+1/an 已知数列{an}满足a1=1,an=a1+2a2+3a3.+(n-1)an-1 (n>=2),则{an}的通项是什么