等差数列{an}中an=2n+1,等比数列{bn}满足b1=a2,b2=a4求{bn}前n项和Sn
等差数列{an}中an=2n+1,等比数列{bn}满足b1=a2,b2=a4求{bn}前n项和Sn
an等差数列 bn前n项和sn满足sn=3(bn-1)/2 且a2=b1 a5=b2 ⑴求an bn通项 ⑵设tn为数列
已知等差数列{an}的首项a1≠0,前n项和为Sn,且S4+a2=2S3;等比数列{bn}满足b1=a2,b2=a4 (
已知等差数列an的首项a1≠0,前n项和为Sn且S4+a2=2S3,等比数列{bn}满足b1=a2,b2=a4 1.若a
已知数列{an}的前n项和公式为Sn=n^2 -2n .若等比数列{bn}中,b1=a2 ,b2=a3,求b7
an为等差数列,bn为等比数列,a1=b1=1,a2+a4=b3,b2*b4=a3,求an的前10项和及bn
设数列an的前n项和为Sn=2n∧2,bn为等比数列,且a1=b1,b2(a2-a3)=b1(1)求数列an和bn的通项
已知an为等差数列,且a2=-8,若等差数列bn满足b1=-8,b2=a1+a2+a3,求bn的前n项和Tn.
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
数列{an}的前n项和为Sn等于2n^2,{bn}为等比数列,且a1=b1,b2(a2-a1)=b1,求an和bn的通项
数列{an}的前n项和为Sn=2n²,{bn}为等比数列,且a1=b1,b2(a2-a1)=b1,求an和bn
设数列an前n项和Sn=2n^2,bn为等差数列,且a1=b1,b2*(a2-a1)=b1.设cn=an/bn,求数列c