设Sn为等差数列前n项和,求证:{Sn/n}是等差数列

设Sn为等差数列an的前n项和.求证Sn/n为等差数列 设Sn为等差数列前n项和,求证:{Sn/n}是等差数列 设Sn为等差数列{An}的前n项和,求证：{Sn/n}是等差数列 一道关于等差数列的题设Sn为等差数列｛An｝的前n项和 求证：数列｛n分之Sn}是等差数列 已知an是等差数列,前n项和为Sn,求证:S3n=3(S2n-Sn) 设等差数列{an}的前n项和为Sn 若a1=Sn> 设数列【An】的前n项和为Sn,A1=10,An+1=9Sn+10.设Bn=lgAn,求证数列【Bn】为等差数列 (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 设Sn是等差数列｛an｝的前n项和,求证：若正整数m,n,p成等差数列,则Sm/m,Sn/n,Sp/p也成等差数列. 已知数列{bn}前n项和为Sn,且2(Sn-n)=n*bn,求证{bn}是等差数列. 设等比数列｛an｝的公比为q,前n项和为Sn,若Sn+1,Sn,Sn+2成等差数列,则q的值为 设等比数列{An}的公比为q,前n项和为Sn,若Sn+1,Sn,Sn+2成等差数列,则q的值为（） 关于等差数列的题设数列{An}的前n项和为Sn,已知A1=1,且满足3Sn^2=An(3Sn-1)(n≥2)(1)求证:数列{1/Sn}是等差数列(2)设bn=Sn/3n+1,求数列{bn）的前n项和n 设等比数列an的公比为q 前n项和为Sn 若Sn+1 Sn Sn+2成等差数列 则q的值 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 设等差数列{an}公差d是2,前n项和为Sn,则lim(an^2-n^2)/Sn 设等差数列{an}公差d是2,前n项和为Sn,则lim(an^2-n^2)/Sn 设等差数列前N项的和为SN,若SN=SM,则S(M+N)=?