设{an}满足a1=3,an+1=1/2(an+1) 是否存在k,使数列{an-k}成等比数列,若存在,求出k的值.若不存在,说明理由.（2）若要使an《=1025/1024成立,求n取值范围

设数列AN满足A1等于1,3(A1+a2+~+AN)=(n+2)an,求通向公式 数列{an}满足a1=3/2,an+1=an2-an+1,求证：1/an=1/(an)-1 - 1/(an+1)-1数列{an}满足a1=3/2,an+1=an2-an+1,求证：1/an=1/(an)-1 - 1/(an+1)-1设Sn=1/a1+1/a2+...+1/an,n>2证明1 设数列【an】满足a1=1,3（a1+a2+a3+······+an）=（n+2）an,求通项an 数列AN满足A1=2,AN+1=AN^2+6AN+6,设CN=LOG5(AN+3),证｛CN}为等比 设数列{an}满足a1=1, an=(4an-1 +2)/(2an-1 +7) ,则通项xn=? 数列｛an｝满足a1=1,且an=an-1+3n-2,求an 已知{an}满足a1=1.an=3*n+2An-1,求an 设数列an满足a1=2,a(n+1)=3an+2^(n-1),求an2,设数列an满足a1=2,a(n+1)=3an+2n,求an 数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an 数列{an}满足a1=3/2,an+1=an2-an+1,求证：1/an=1/(an)-1 - 1/(an+1)-1 设Sn=1/a1+1/a2+...+1/an,n>2数列{an}满足a1=3/2,an+1=an2-an+1,求证：1/an=1/(an)-1 - 1/(an+1)-1设Sn=1/a1+1/a2+...+1/an,n>2证明1 已知数列{an}满足a1=1 an+1=an/(3an+1) 则球an 设数列{an}满足lg(1+a1+a2+...+an)=n+1,求通项公式an 已知数列an满足 a1=1/2,an+1=3an/an+3求证1/an为等差数列已知数列an满足 a1=1/2,an+1=3an/an+3求证1/an为等差数列 设数列{an}满足a1=1a2=2an=1/3（an-1+2an-2）求an题目为设数列{an}满足a1=1，a2=2，an=1/3（an-1+2an-2）求an 数列 (10 18:35:56)设数列{an}满足a1=9,an+1=-1/2an+3,求an的通项公式（含过程） 已知数列{an}满足a1=1,a2=3,an+2=3an+1-2an求an 设数列｛an｝满足a1+2a2+3a3+.+nan=n(n+1)(n+2)求通项an 数列{an}满足a1=a,an+1=1+1/an.若3/2