数列an满足a1=1,a2=r>0且数列ana(n+1)是一个以q为公比的等比数列,设bn=a(2n-1)+a2n,Sn=b1+b2+…+bn,求bn及Sn

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=2且anan+1-2an=0球a2,a3,a4的值 已知数列an 满足条件：A1=1,A2=r（r＞0）数列{an+an+1}是公差为d的等差数,求a1+a2.+a2n-1+a2n 数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an 若数列{an}满足a1=1,a2=5且an+2=an+1-an,求a2000 (1/2)已知数列an满足条件：a1=1.a2=r.(r>0)且{anan+1}是公比为q的等比数列,设bn=a2n-1+a2n,求数列bn的前 已知数列{an}满足:a1=1,且an-an-1=2n,求(1)a2,a3,a4.(2)求数列{an}的通项an 已知数列an满足an=1+2+...n,且（1/a1）+(1/a2）+...(1/an) 数列[An]满足An+1-An+3=0,且A1=-5.求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=? 已知数列｛an｝满足：a1=1,且an-a（n-1）=2n.求a2,a3,a4.求数列｛an｝通项an 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 已知递增数列{an}满足a1=1,(2an+1)=an+(an+2),且a1,a2,a4成等比数列.求an 设数列an满足条件a1=8,a2=0,a3=-7且数列an+1 -an是等差数列,求数列的最小项是第几项?如题,请具体讲解 已知数列an满足a1=0 a2=1 an=(An-1+An-2)/2 求liman 已知数列an满足a1=0 a2=1 an=(An-1+An-2)/2 求liman 根据下列条件,确定数列{an}的通项公式1.在数列｛an｝中,a(n+1)=3an^2,a1=32.在数列｛an｝中,a1=2,a(n+1)=4an-3n+13.在数列｛an｝中,a1=8,a2=2,且满足a(n+2)-4a(n+1)+3an=0 数列an满足a1=1,a(n+1)=r*an+r(r≠0),则r=1是数列an成等差数列的什么条件