a1=1.an／an-1=3n n＞1求通项公式

已知{an}满足a1=1.an=3*n+2An-1,求an 数列｛an},a1=1,an+1=2an-n^2+3n,求｛an｝. 数列an满足a1=1/3,Sn=n(2n-1)an,求an 数列{an},a1=3,an*a(n+1)=(1/2)^n,求an a1=1,an+1=an+3^n-n,求an与sn 在数列｛an｝中,a1=3,a(n+1)=an+n,求an 已知数列｛an｝中,a(n+1)=an+2^n,a1=3,求an a1=1,an+1=an/(3+an),求an=?（n为下标） an+1 ,n+1是下表 ,an+1=an^3 a1=2 ,求an 数列｛an｝满足a1=1,且an=an-1+3n-2,求an 数列{an}中,a1=1,an+1/an=n/n+2,求an 已知a1=2 a(n+1)=2an+2^n+3^n 求an 数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an 1、在数列{an}中,a1=1.a(n+1)=3an+2n+1.求an.2、在数列{an}中,a1=-1,a(n+1)=(3an-4)/[(an)-1].求an. 1.a1=1,an+1=an+2n-1,求an 2.a1=1,an+1=2an+2n-1,求an 3.a1=1,an+1=3an+3n,求an4.a1=1,an+1=3an+6,求an就这4个,用累加或累乘的方法做 已知数列（an）满足a1=1.an+1=3an+2n-1,求an a1=1.an／an-1=3n n＞1求通项公式 a1=1,Sn=n^2an,求an