已知数列{an}满足a1=2,sn=4a的n-1 +2（n=2,3,4,.） （1）证明数列{a的n-1 - 2a的n}成等比数列

已知数列{an}满足:a1=3,an=Sn-1+2n,求数列an及sn 已知数列{an}满足a1=1/2,sn=n^2an,求通项an 已知数列{an},满足a1=1/2,Sn=n²×an,求an 已知数列an满足a1=1/2 sn=n平方×an 求an 已知数列An满足 A1=1/2 Sn=N²An 求An 已知数列an满足a1=1 Sn=2an+n 求an 已知数列{an}满足,a1=2,a(n+1)=3根号an,求通项an数列{an}满足:an>0,且根号下Sn=an+1/4,求通项an 已知数列｛an｝满足an+1+an=4n-3 当a1=2时,求Sn 已知数列an满足a1=1 ,Sn=(n+1)*an/2,求通项 的表达式. 已知数列｛an｝满足a1=1,a（n+1）=sn+（n+1）求：an和sn 已知sn为数列an的前n项和,其中满足a1=4,an=3an-1-2,求an及sn 已知数列{an}满足a1=1,a(n+1)an=2^n,Sn是数列{an}的前n项和,S2012是多少? 已知数列{an}满足a1=1,a(n+1)an=2^n,Sn是数列{an}的前n项和,S2012是多少? 已知数列{an}满足a1+a/4,(1-an)a(n+1)=1/4,令bn+an-1/2 求证数列{1/bn}为等差数列,求和:Sn=a2/a1+a3/a2+...+a(n+1)/an已知数列{an}满足a1=1/4,(1-an)(a(n+1))=1/4,令bn=an-1/2 求证数列{1/bn}为等差数列，求和:Sn=a2/a1+a3/a2+... 已知数列an的前n项和sn与通项an满足a1=2,sn+1sn=an+1,求sn 数列{an}满足Sn+Sn+1=5/3an+1,a1=4求an 超难数列题哦已知数列{an}的前n项和为Sn,且数列{an}满足Sn=1/2a(n-1)首项a1=1,求数列{an}通项公式 已知数列{an}满足a1=1,a(n+1)=3an+2,求数列{an}的前n项和Sn.求数列{an}的前n项和Sn.