设数列{An}的前n项和为Sn若An+1=3Sn,a1=1则a6=

设数列an的前n项和为Sn,若Sn=1-2an/3,则an= 数列｛an｝,中,a1=1/3,设Sn为数列｛an｝的前n项和,Sn=n（2n-1）an 求Sn 设数列{an}的前n项和为Sn,若Sn=1-2/3an,n∈N*,则an= 设数列{an}的前n项和为Sn,若a1=1,Sn=2an+Sn+(n∈N+),则a6= 数列an的前n项和为Sn,若an+sn=n,设cn=an-1,求证cn是等比数列 数列an的前n项和为Sn,若an+sn=n,设cn=an-1,求证cn是等比数列 设数列{an}的前n项和为Sn,Sn=n-an,n属于自然数.求:证明:数列{an-1}是等比数列 (1/2)设数列[an]的前n项和为Sn,已知a1＝1,Sn+1=2Sn+n+1.1,求数列[an]的通项公式.2,若bn=n/an+1-an, 设数列{An}的前n项和为Sn若An+1=3Sn,a1=1则An= 设数列An的前n项和为Sn,已知a1=1,An+1=Sn+3n+1求证数列｛An+3}是等比数列 设数列{an}的前n项和为sn,若an=n+1/2^n,(1)求s10(1)求sn 【高考】若数列{an}满足,a1=1,且a(n+1)=an/(1+an),设数列{bn}的前n项和为Sn,且Sn=2-bn,求{bn/an}的前...【高考】若数列{an}满足,a1=1,且a(n+1)=an/(1+an),设数列{bn}的前n项和为Sn,且Sn=2-bn,求{bn/an}的前n项和Tn 设数列an的前n项和为Sn,满足an+sn=An^2+Bn+1(A不等于0)an为等差数列,求(B-1)/A 设数列｛an｝的前n项和为Sn 已知1/S1+1/S2+ 设数列An的前n项和为Sn,且a1=1,An+1=1/3Sn,求数列an的通项公式. 设数列an的前n项和为Sn,已知a1=1,3an+1=Sn,求数列an的通项公式 设数列an的前n项和为Sn,已知a1=1,3an+1=Sn,求数列an的通项公式 设数列an的前n项和为Sn,且2an=Sn+2n+1 求a1 a2 a3 求证:数列{an+2}是等比数列 求数列{n*an}的前n项和Tn