已知数列an满足bn=an-3n,且bn为等比数列,求an前n项和Sn
已知数列an满足bn=an-3n,且bn为等比数列,求an前n项和Sn
已知等比数列{an},首项为81,数列{bn}满足bn=㏒3an,其前n项和为Sn,求证﹛bn﹜为等差数列.
数列an的前n项和为Sn,Sn=4an-3,①证明an是等比数列②数列bn满足b1=2,bn+1=an+bn.求数列bn
已知等比数列an,首项为81,数列bn满足bn=log3an,其前n项和sn
已知等比数列an,首项bn满足bn=log3an,其前n项和为Sn
已知数列an满足;a1=1,an+1-an=1,数列bn的前n项和为sn,且sn+bn=2
已知数列an的前n项和为sn,满足an+sn=2n,记bn=2-an,求证bn是等比数列,并求bn的
已知数列an的前n项和为Sn,若Sn=2an+n,且bn=An-1/AnAn+1,求证an-1为等比数列;求数列{bn}
设数列an前n项和为Sn,且an+Sn=1,求an的通项公式 若数列bn满足b1=1且bn+1=bn+an,求数列bn通
已知数列{an}的前n项和Sn=n2(n∈N*),数列{bn}为等比数列,且满足b1=a1,2b3=b4
已知两个数列﹛an﹜,﹛bn﹜,满足bn=3^n*an,且数列﹛bn﹜的前n项和为Sn=3n-2,则数列﹛an﹜的通项公
an=2*3^n-1 若数列bn满足bn=an+(-1)^n*ln(an),求数列bn前n项和Sn