设i是虚数单位,计算1-i分之1+i= 设Sn 是数列{an}的前n项和,若a1=1,an=Sn-1(n大于等于2),则
设Sn是数列an的前n项和,已知a1=1,an=-Sn*Sn-1,(n大于等于2),则Sn=
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,若a1=1,Sn=2an+Sn+(n∈N+),则a6=
设数列an的前n项和为Sn,a1=1,an=(Sn/n)+2(n-1)(n∈N*) 求证:数列an为等差数列,
设数列An的前n项和为Sn,已知a1=1,An+1=Sn+3n+1求证数列{An+3}是等比数列
设数列{an}的前n项和为Sn,若a1=1,an+1=3Sn(n∈N*),则S6=( )
设数列an的前n项和为Sn,已知a1=1,Sn+1=4an+2
设数列an的前n项和为Sn,a1=1 ,an = 2Sn²/2Sn-1 (n≥2)
设数列{an}的前n项和为Sn,若a1=1,a(n+1)=(n+2/n)Sn(n属于正整数),证明:数列{Sn/n}是等
已知数列{an}的前n项和满足a1=1/2,an=-Sn*S(n-1),(n大于或等于2),求an,Sn
数列{an}中,a1=1,当n大于等于2时,其前n项的和Sn,满足Sn的平方=an(Sn-1)
已知数列【An】的前n项和为Sn,A1=-3分之2,满足Sn+Sn分之1+2=An(n大于等于2).计算S1,S2,S3