2Sn+Sn-1=3-8/2^n,求Sn

2Sn+Sn-1=3-8/2^n,求Sn Sn=3+2^n Sn-1=3+2^(n-1).则Sn-Sn-1=? 数列{an}前n项和为Sn,且2Sn+1=3an,求an及Sn 高二数学数列求和问题!在数列an中,a1=1,Sn为an前n项和,an=S(n-1) 求Sn,an请帮我看看我分别先算Sn和an哪里出错了?1.先算Sn因为an=2Sn-1 且an=Sn-Sn-1所以 Sn-Sn-1=2Sn-1Sn=3Sn-1所以Sn是一个等比数列 公比为3 运 sn=2*3^n,求an 1+2+3+4+.+n,求Sn 数列求和:sn=1+1/2+1/3+…+1/n,求sn 设：Sn=1+2+3….n(n∈N),求：f(n)=Sn/(n+32)Sn+1的最大值. 已知an=(2n+1)*3^n,求Sn 已知数列 an前n项和为Sn,a1=1,Sn=2a(n+1),求Sn 已知数列前n项和为Sn,且Sn=-2n+3,求an及Sn 正数列{bn}前n项和Sn·且Sn=1/2(bn+n/bn)求Sn 已知数列an的前n项和Sn,求数列的通项公式.(1)Sn=3n²-n (2)Sn=2n+1 Sn为数列{an}前n项和,(2n-1)Sn+1-(2n+1)Sn=-4n-3 ,求{an}通项公式 Sn=1/2n∧2+1/2n 求sn/s(n+1) a1=1/2,Sn=n^2an-n(n-1),求Sn和an 已知数列an中,a1=2,a2=3,其前n项和Sn满足Sn +1+Sn -1=2Sn +1,求an的通项公式.补充：n＞＝2,前面不太正确,是：其前项和Sn满足Sn+1 +Sn-1 =2Sn +1 已知数列{an}的前n项和为Sn=1+2+3+4+…+n,求f(n)= Sn /(n+32)Sn+1的最大值f(n)= Sn /(n+32)Sn+1 Sn为分子...(n+32)Sn+1 为分母...看不出来么?