a1=9,3a(n+1)+an=4.Sn为an前n项和,求|Sn-n-6|

数列{An},A1=1,A(n+1)=3An+4.求An和Sn. a1=9,3a(n+1)+an=4.Sn为an前n项和,求|Sn-n-6| 设数列{an}的前n项和为Sn,a1=10,a(n+1)=9Sn+10 等差数列前n项和为Sn,若a（n+1）=3Sn,a1=1,则通项an? 数列an满足a1=1/3,Sn=n(2n-1)an,求an a1=1,an+1=an+3^n-n,求an与sn 已知数列{an},其中a1=1,a（n+1）=3^(2n-1)*an(n∈N),数列{bn}的前n项和Sn=log3(an/9^n)(n∈N)求an bn 已知数列 an前n项和为Sn,a1=1,Sn=2a(n+1),求Sn 数列{an}的前n项和为Sn,若a1=1,Sn=3a n+1 ,则Sn等于:n+1是脚标 设数列an的前n项和为Sn,满足an+Sn=An^2+Bn+1（A不等于0）,a1=3/2,a2=9/4,求证an-n为等比数列并求an 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 在数列An中 已知A1=-1 A(n+1)=Sn+3n-1求An a1=1,Sn=n^2an,求an 已知数列｛an｝满足a1=1,a（n+1）=sn+（n+1）求：an和sn 设数列an的前n项和为Sn,已知a1=1,(2Sn)/n=a(n+1)-1/3n^2-n-2/3 a1=1/2,Sn=n^2an-n(n-1),求Sn和an 已知数列an满足a1=1,a（n+1）=an/{3（an）+1} Sn=a1a2+a2a3+.+an（an+1）,求Sn已知数列an满足a1=1,a（n+1）=an/{3（an）+1}Sn=a1a2+a2a3+......+an（an+1）,求Sn an=a1+(n-1)d 和Sn=n(a1+an)/2中an是什么意思?