Bn=(2n-1)/2^n,Tn=B1+B2+B3+...+Bn,Tn

Bn=(2n-1)/2^n,Tn=B1+B2+B3+...+Bn,Tn An=2n-1,设Bn=An/2ˇn,Tn=B1+B2+B3+.+Bn,若Tn Tn=b1+b2+b3+.bn,bn=（2n+1）乘以2的n次方,求Tn bn=1/(2^n +1)(2^(n+1)+1),Tn=b1+b2+……+2^(n-1)bn,求证Tn小于1/6是Tn=b1+2b2+……+2^(n-1)bn 数列 an=2n-1 设bn=an/3^n 求和tn=b1+..bn? 数列an=(1/2)^n,数列{bn}满足 bn=3+log4an ,设Tn=|b1|+|b2|+...+|bn|,求Tn ． 已知数列｛bn｝满足b1=2,nbn+1=(n+1)bn+2(n属于n+).求数列bn的通项公式.(2)设数列bn的前n项和为Tn,求Tn 令bn=1/（n2+2n） Tn=b1+b2+b3+……+bn 求1/3 已知数列{bn}满足bn+1=1/2bn+1/4,且b1=7/2,Tn为{bn}的前n项和.12k/(12+n-2Tn)>=2n-7,求k的范围. 已知数列bn满足b1=2,nbn+1=（n+1）bn+2（n属于正整数）.1,求通项公式bn.2,设bn的前n项和为Tn,求Tn 已知an=√1/(4n-3)?{bn}的前n项和为Tn?Tn+1/(an)^2=Tn/(an+1)^2+16n^2-8n-3?求当b1为多少时,{bn}为...已知an=√1/(4n-3)?{bn}的前n项和为Tn?Tn+1/(an)^2=Tn/(an+1)^2+16n^2-8n-3?求当b1为多少时,{bn}为等差数列 an=2^n bn=2n Tm=b1/a1+b2/a2+……+bn/an,求Tn 等比数列bn=0.5*2^(n-1) Tn=b1*b2*b3.bn ,求Tn的通项公式如题 已知bn+1=bn^2-(n-2)bn+3,bn≥n(n∈正整数),求证:Tn=1/(3+b1)+1/(3+b2）+……+1/(3+bn) 3.设数列{an}的前n项和Sn=2an-4(n∈N+),数列{bn}满足:bn+1=an+2bn,且b1=2.求{bn}前n项的和Tn. 数列bn的前n项和为Tn,6Tn=(3n+1)bn+2,求bn 已知数列bn满足bn=b^2n,其前n项和为Tn,求(1-bn)/Tn bn=2^(2n-1)-2n,求{bn}的前n项和Tn