1/2)设Sn是正项数列【an】的前n项和,4Sn=an^2+2an-3.已知bn=2^n,求Tn=a1b1+a2b2+

设Sn是数列{an}的前n项和,所有项an>0,且Sn=n^2+2n,已知bn=2^n,求Tn=a1b1+a2b2+…… 设数列{An}的前n项和为Sn=n平方,1.求数列的通项公式2.已知Bn=2^n,求Tn=a1b1+a2b2+...+a 数列an的n项和sn=a^2n/4+an/2-3/4 1.求通向公式 2.已知bn=2^n,求Tn=a1b1=a2b2= 已知数列{an},{bn}的前n项和Sn、Tn,Sn=2n平方+3n,Tn=2-bn求通项公式an,bn 数列an,满足Sn=n^2+2n+1,设bn=an*2^n,求bn的前n项和Tn 数列{an}的前n项和为Sn=3an+2 设bn=n 求数列{an·bn}的和Tn 已知数列an的前n项和Sn=n^2,设bn=an/3^n,记数列bn的前n项和为Tn. 已知数列{an}的前n项和sn=n^2,设bn=an/3^n,记数列{bn}的前n项和为Tn 已知数列an的前n项和Sn=n^2,设bn=an/3n,记数列bn的前n项和为Tn 已知数列{an}的前N项和为Sn 且an+1=Sn-n+3,a1=2,设Bn=n/Sn-n+2前N项和为Tn 求证Tn 已知数列{an}前n项和Sn=n^2+n,令bn=1/anan+1,求数列{bn}的前n项和Tn 数列{an},a1=1,an=2-2Sn,求an,若bn=n*an,求{bn}的前n项和Tn