设数列an的前n项和为Sn,Sn-tSn-1=n,a1=1(1)t=2,求a2,a3(2){an+1}是等比数列,求t的值(3)求sn

设数列an的前n项和为Sn,Sn-tSn-1=n,a1=1(1)t=2,求a2,a3(2){an+1}是等比数列,求t的值(3)求sn 设数列{an}满足a1=t,a2=t^2,前n项和为Sn,且Sn+2－(t＋1)Sn+1＋tSn＝0(n属于N*)（1）证明：数列{an}为等比数列,并求出数列{an}的通项公式（2）当1/2 设数列{an}满足a1=t,a2=t^2,前n项和为Sn,且Sn+2－(t＋1)Sn+1＋tSn＝0(n属于N*)（1）证明：数列{an}为等比数列,并求出数列{an}的通项公式（2）当1/2 合情推理设正数列{An}前n项和为Sn 且存在正数t 使得对所有自然数n 有√（tSn）=（t+An）/2 则通过归纳猜想可得到Sn= 1.设数列｛an｝的前n项和为Sn,其中an≠0,a1为常数,且-a1,Sn,an+1(n+1是a的下标啊,我打不出来）成等差数列,求｛an｝的通项公式2.数列｛an｝中,a1=1,Sn为其前n项的和,当t>0时,有3tSn-(2t+3)Sn-1=3t(n-1是S的下 设数列{an}满足a1=t,a2=t的平方,前n项和为Sn,且Sn+2-（t+1）Sn+1+tSn=0设数列｛an｝满足a1=t,a2=t^2（其中t为非零常数）,前n项和为Sn且Sn+2－(t＋1)Sn+1＋tSn＝0(n属于N*)求证1/b1+1/b2+…+1/bn若1/2＜t＜2，bn=2an/( 数列｛an｝,中,a1=1/3,设Sn为数列｛an｝的前n项和,Sn=n（2n-1）an 求Sn 设数列an的首项a1=1,前n项和Sn=满足关系式tSn-(t+1)S(n-1)=t (t大于0,n属于N* n大于等于2) 求证：数列an是等比数列 设数列an的前n项和为Sn,若Sn=1-2an/3,则an= 设数列｛an｝的前N项和为Sn,已知1/Sn+1/S2+1/S3+.+1/Sn=n/(n+1),求Sn 求:设数列 {an}的前n项和为Sn,数列{Sn}的前n项和为Tn,满足Tn=2Sn一n²,n∈求:设数列 {an}的前n项和为Sn,数列{Sn}的前n项和为Tn,满足Tn=2Sn一n²,n∈N 设数列an的首项a1等于1,前n项和为sn,sn+1=2n设数列an的首项a1等于1，前n项和为sn，sn+1=2n 设数列{an}的前n项和为Sn,满足Sn-tSn-1=n(n大于等于2,n属于N),t为常数,且a1=1.(1)当t=2时,求a2和a3;(2)若{an +1}是等比数列,求t的值; 设数列(an)de 首项a1=1,前n项和Sn满足3tSn-(2t+3).Sn-1=3t(t>0,n=1,2,3,4,...)证明数列an是等比数列 设数列{an}的前n项和为Sn,a1=10,a(n+1)=9Sn+10 设数列{an}的前n项和为Sn,已知ban-2n=(b-1)Sn 设等比数列an的公比为q前n项和为Sn若Sn+1,Sn,Sn+2成等数列,求q 设等比数列{an}的公比为q,前项和为sn,求数列{sn}的前n项和un