等差数列{an}中,前n项和是Sn,且S5S8,则下列错误的是________
等差数列{an}中,前n项和是Sn,且S5S8,则下列错误的是________
等比数列{an}中若a1=1,且前N项和SN构成等差数列,则等差数列{sn}的公差是?
等差数列an中,a50,且a6>/a5/,sn为数列an的前n项和,则使sn>0的n的最小值是
等差数列{an}的前n项和Sn满足S20=S40,下列结论中一定正确的是( )
设Sn是数列an的前n项的和,且Sn=n^2,则an是等差数列还是等比数列?
已知数列{an}中,a2=2,前n项和为Sn,且Sn=n(an+1)/2证明数列{an+1-an}是等差数列
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是等差数列,且a1不等于0,Sn为这个数列的前n项和,求limnan/Sn.limSn+Sn-1/Sn+Sn
已知数列{an}的前n项和为Sn,且满足Sn=Sn-1/2Sn-1 +1,a1=2,求证{1/Sn}是等差数列
数列{an}中,a2=2,前n项和为sn,且sn=n(an+1)/2 证明{a-an}是等差数列
等差数列{an}中,a1>0,3a4=7a7,sn是数列{an}的前n项和,则sn取得最大值是n=
在等差数列{an}中,a1=1,Sn是前n项和,且S1,S3,S8成等差数列,求a23+2S23的值(要求详细解答)