已知数列an前n项和Sn满足an+2SnS(n-1)=0 a1=1 求Sn

已知数列{an}的前n项和sn满足sn=an^2+bn,求证{an}是等差数列 已知数列an的前n项和sn满足sn=n的平方+2n-1求an 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的前n项和Sn满足：Sn=2n-an 求通项公式 一个数列问题已知数列an前n项为sn,满足an+sn=2n.求an 已知数列｛an｝的前n项和为sn,且满足sn＝n 已知数列{an}的前n项和Sn满足Sn=2/3an-1/3,且1 (1)已知数列an的前n项和为sn满足sn=an²+bn,求证an是等差数列(2)已知等差数列an的前n项和为sn,求证数列sn/n也成等差数列 已知数列{an}的前n项和为Sn,且满足Sn=2an-1(n属于正整数),求数列{an}的通项公式an 已知数列（an）的前n项和为Sn,满足an+Sn=2n,证明数列(an-2)为等比数列并求出an 已知数列An的前n项和Sn满足An+2Sn*Sn-1=0,n大于等于2,A1=1/2,求An. 已知数列{an}的前n项和为Sn,且满足an+2Sn*Sn-1=0,a1=1/2.求证：{1/Sn}是等差数列 已知数列{an}a1=2前n项和为Sn 且满足Sn Sn-1=3an 求数列{an}的通项公式an已知数列{an}a1=2前n项和为Sn 且满足Sn +Sn-1=3an 求数列{an}的通项公式an 已知数列{an}的前n项和为Sn,an+Sn=2,（n 已知数列{an}满足an=2n/3^n,求此数列的前n项和sn 已知数列{an}中,an>0,前n项和为Sn,且满足Sn=1/8(an+2)^2.求证数列{an}是等差数列. 已知数列的前n项和sn满足2sn-3an+2n=0(n 已知数列{an}的前n项和为Sn,通项an满足Sn+an=1/2(n²+3n-2)求通项公式an