若等差数列An的前n项和为Sn,且满足Sn/S2n为常数,则称该数列为S数列 判断An＝4n-2是否为S数列?说明理由

设等差数列{an}的前n项和为Sn,且满足S15>0,S16 若等差数列｛an｝的前n项和为Sn,且满足Sn/S2n为常数,则称该数列为S数列 若首项为a1的各项为正数的等差数列{an}是S数列,设n+h=2008,（n,h为正数） 求1/Sn+1/Sh的最小值 Sn、Sh分别是数列的前n项和和 若等差数列An的前n项和为Sn,且满足Sn/S2n为常数,则称该数列为S数列 判断An＝4n-2是否为S数列?说明理由 已知数列{an}的前n项和为Sn,且满足an+2Sn*S(n-1)=0 (n>=2),a1=0.5.(1)求证：{1/Sn}是等差数列 （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｝的前n项和为Sn,且满足an+2Sn×S(n-1)=0,a1=1/2.（1）求证：｛1/Sn｝是等差数列；（2）求数列｛an｝的通项公式. 等差数列{an}的前n项和为Sn,且满足Sn=S(19-n),(n属于自然数且小于19）,当绝对值an最小时候,n=多少?感激不尽 已知等差数列an的前n项和为sn 且满足Sn=n²+n,则通项公式an=? 短时间内一定采纳,谢谢）已知数列{An}的前n项和为Sn且满足an=2S(n-1)Sn(n>=2),a1=1.已知数列{An}的前n项和为Sn且满足an=2S(n-1)Sn(n>=2),a1=1.(1)求证:{1/Sn}是等差数列(2)求an的表达式.(1)里是怎样做到 1/(sn) - 已知等差数列an的前n项和为Sn,且满足a2+a4=14,S7=70 等差数列{An}的前n项和为Sn,且满足A3*A4=117,A2+A5=22 求通项An ；若数列{Bn}是等差数列,且Bn=Sn/(n+c),求 求证等差数列!已知数列an的各项均为正数,前n项和为Sn,且满足2Sn=a∧2n+n-4 数列﹛an﹜的前n项和为Sn,且Sn＝30,S₂n＝90,若﹛an﹜是等差数列,求S₃n.若﹛an﹜是等比数列,求S₃n. 设数列[an}的前n项和为Sn,已知a1=1且满足3Sn的平方=an(3Sn-1),1求{1/Sn}为等差数列 1.求{1/Sn}为等差数列2.若bn=Sn/3n+1,数列{bn}的前n项和为Tn,求Tn 已知数列an的前n项和为Sn,且满足an+2Sn·S(n-1)=0(n≥2),a1=1.5⑴求证1/Sn是等差数列⑵求an的表达式⑶若bn=2(1-n)·an(n≥2)求证b2·b2+b3·b3+…+bn·bn (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 设无穷等比数列an的前n项和为sn,所有项的和为s,且满足s=an+sn,则an的公比是? 已知数列an的前n项为Sn,且满足Sn=S(n-1)/2S(n-1)+1(n≥2）,a1=2(1)求证:{1/Sn}是等差数列(2)求an的表达式.