已知数列an满足a1=1.a2=3,an+2=3an+1-2an（3）若数列bn满足4^(b1-1)*4^(b2-1)…4^(bn-1)=（an+1)^bn,证明bn是等差数列

已知数列an满足a1=1,a2=3,an+1.an-1=an,求a2013 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+a2+...+an=n²an求其通项an 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=½,a1+a2+.+an=n²an,求其通项an 已知数列{an}满足a1=½,a1+a2+.+an=n²an,求其通项an 已知数列{an}满足：a1+a2+a3+.+an=n^2,求数列{an}的通项an. 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a1=1 an+1=an/(3an+1) 则球an 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,An+1=2An+1.求A1+A2+A3+…+An的值 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 已知数列{an}满足a1=1,an=a1+2a2+3a3+……+(n-1)an-1 (n≥2)求an=? 已知,数列{an}满足a1=1,an+1=3an +1,证明:1/a1+1/a2+…+1/an 【高中数学数列】已知数列an满足a1=1,a2=2,且an=an-1/an-2 (n大于等于3)则a2012=? (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=1/2,a1+a2+a3+...+an=n^2an,求通项公式 已知数列{an}满足关系式lg（1+a1+a2+.+an）=n,求数列{an}的通项公式