在等比数列{an}中,a1=1,公比为q,且|q|≠1.若am=a1a2a3a4a5,则m=__________.

数列{an}的前n项和为Sn,已知Sn=1-2+3-4+…+(-1)n-1·n,则S17=__________.

(2014·重庆模拟)已知等差数列{an}满足a2+a4=4,a3+a5=10,则它的前6项的和S6=________.

已知数列{2n-1·an}的前n项和Sn=9+2n,则数列{an}的通项公式为an=________.

已知函数f(x)对应关系如表所示,数列{an}满足a1=3,an+1=f(an),则a2015=________.

数列{an}的前n项和记为Sn,a1=t,点(Sn,an+1)在直线y=2x+1上,n∈N*,若数列{an}是等比数列,则实数t=______.

已知函数f(x)=2x,等差数列{an}的公差为2,若f(a2+a4+a6+a8+a10)=4,则log2[f(a1)·f(a2)·f(a3)·…·f(a10)]=________.

设{an}是公比为正数的等比数列,a1=2,a3=a2+4.

(1)求{an}的通项公式.

(2)设{bn}是首项为1,公差为2的等差数列,求{an+bn}的前n项和Sn.

已知数列{an}满足an+1=(n∈N*),且a1=.

(1)求证：数列是等差数列,并求an.

(2)令bn=(n∈N*),求数列{bn}的前n项和Tn.

已知数列{an}为等差数列,a3=5,a7=13,数列{bn}的前n项和为Sn,且有Sn=2bn-1,

(1)求{an},{bn}的通项公式.

(2)若cn=anbn,{cn}的前n项和为Tn,求Tn.