已知数列｛An｝满足A1=1.A2=3,3/2An+1是An+2与2An的等差中项（1）证明：数列{A(n+1)-An}是等比数列（2）求数列{An}的通项公式（3）若数列4^[(b1)-1]*4^[(b2)-1]…*4^[(bn)-1]=(An+1)^bn证明：数列{An}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. 已知等比数列{an}满足a1+a2=3,a2+a3=6,求这个数列的第7项a7 (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+2a2+3a3+……+nan=2^n,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 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+2a2+3a3+…+nan=n(n+1)(n+2),则a1+a2+a3+…+an=多少? 已知,数列{an}满足a1=1,an+1=3an +1,证明:1/a1+1/a2+…+1/an