数列an,a1=5 an=Sn-1(n大于等于2) 则an_?

数列an满足a1=1/3,Sn=n(2n-1)an,求an 数列an,a1=5 an=Sn-1(n大于等于2) 则an_? 数列an中,a1=1,an=2Sn^2/2sn-1(n大等于2.n属于N*)则sn=? 已知数列{an}满足:a1=3,an=Sn-1+2n,求数列an及sn 在数列an中,a1=1,Sn=n²an,则an= 数列{An},A1=1,A(n+1)=3An+4.求An和Sn. 已知数列{an},满足a1=1/2,Sn=n²×an,求an 已知数列{an}满足a1=1/2,sn=n^2an,求通项an 已知数列an满足a1=1/2 sn=n平方×an 求an 已知数列An满足 A1=1/2 Sn=N²An 求An 已知数列an满足a1=1 Sn=2an+n 求an 数列{an}满足Sn+Sn+1=5/3an+1,a1=4求an 已知数列an中,a1=-2,an+1=Sn(n∈N+),求an和Sn的表达式 数列an,a1=4,Sn+S(n+1)=5/3an+1,an数列an,a1=4,Sn+S(n+1)=5（a（n+1））/3,求an 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 已知数列an中 a1=-2且an+1=sn（n+1为下标）,求an,sn 在数列{an}中,a1=2,an=2an-1+2^n+1 求an和Sn 数列an满足a1=2,an+1=2an+2^n,求an和sn