已知{an}中,a1=1,a2,3an+2-5a(n+1)下标+2an=0,令bn=a(n+1)下标-an,求证{bn}
已知{an}中,a1=1,a2,3an+2-5a(n+1)下标+2an=0,令bn=a(n+1)下标-an,求证{bn}
已知数列{an(n下标)}满足a1(1下标)=1,a2(2下标)=3,.求证:bn(n下标)是等差数列.
在数列an中a1=2,a(n+1)下标=4an-3n+1 1设bn=an-n求证bn是等比数列 2求数列an的前n项和s
a1=1,a2=3,a下标(n+2)=a下标(n+1)-2an,求证{a下标(n+1)-an}为等比数列,并求出an
已知数列{an}中a1=-1且(n+1)an,(n+2)an+1(是下标)成等差数列,设bn=(n+1)an-n+2求证
数列an中,a1=2,an+1=3an-2,bn=an-1,求证bn为等比数列,求an通项公式(n+1为下标)
已知在数列{an}中,a1=2,an=3a[(n-1)](下标)-2,求an
在数列an中,已知a1=2,an+1=2an/an +1,令bn=an(an -1).求证bn的前n项和
1 已知{an}是等差数列,公差d≠0,{bn}是等比数列,a1=b1>0,a(下标:2n+1)=b(下标:2n+1),
已知数列an,bn满足a1=1,a2=3,(b(n)+1)/bn=2,bn=a(n+1)-an,(n∈正整数)
已知数列{an}满足a1=1,a2=2,an+2=(an+an+1)/2,n∈N*.令bn=an+1-an,证明{bn}
数列{an},a1=2,an+1(下标)=an下标+n+1 求通项an下标