设等差数列{an}的前n项和Sn,且S4/S8=1/3,则S8/S16=?

设等差数列An的前n项和为Sn,且S4=4S2,A2n=2An+1 设等差数列{an}的前n项和Sn,且S4/S8=1/3,则S8/S16=? 设等差数列{an}的前n项和为Sn,且S4=20,S8=72,则S12=? 设等差数列an的前n项和为Sn,若S4>=10,S5 设等差数列{an}的前n项和为Sn,a1=3/2,且S1,S2,S4成等差数列,求Sn 设等差数列an的前n项和为Sn,a1=3/2,且s1,s2,s4成等比数列,求sn 设等差数列〔an〕的前n项和为Sn,a1=3/2,且S1,S2,S4成等比数列,求Sn. 设等差数列{an}的前n项和为Sn,且S4=-62,S6=-75求{an}的通向公式an及前n项和Sn,求出前n项和的最小值 设数列(An)是等差数列,且a2=-6,a8=6,Sn是数列(An)的前n项和,求S4,S5,S6. 设｛an｝是等差数列前n项和为Sn,若S4>=10,S5 设Sn是公差不为0的等差数列An的前N项和,且S1.S2.S4.成等比数列.则A2%A1等于? 设数列{an}为等差数列,其前n项和为Sn,且S4=-62,S6=-75求|a1|+|a2|+……+|a14|的值 设数列{an}为等差数列,其前n项和为Sn,且S4=-62,S6=-75求|a1|+|a2|+……+|a14|的值 设Sn是公差不为0的等差数列an地前n项和且S1,S2,S4成等比数列,则a1/a2等于 设Sn为等差数列{an}的前n项和,S4=14,S20-S8=30,则S8=设Sn为等差数列{an}的前n项和,S4=14,S20-S7=30,则S8= 数列推导设等差数列An的前n项和为Sn,则S4,S8-S4,S12-S8,S16-S12成等差数列,设等差数列An的前n项和为Sn,则S4,S8-S4,S12-S8,S16-S12成等差数列,类比以上结论有:设等比数列Bn的前n项积为Tn,则T4,T8/T4,T12/T8,T16/T 设Sn为等差数列an的前n项和,S4=14,S10-S7=30,则S9= 设sn为等差数列（an）的前n项和,s4=14,s10-s7=30.则s9...