若等差数列an满足anan+1=n2+3n+2,则公差为?
若等差数列{an}满足an×an+1=n²+3n+2,则公差为1,还是±1?求详解,
等差数列{1\an}满足a1=1,公差d=2,求a1a2+a2a3+……+anan+1的和
已知数列{an},若1/a1a2+1/a2a3+…+1/anan-1=n/anan+1,求证{an}为等差数列.
已知{an}是公差为d的等差数列,它的前n项和为Sn,S4=2S2+4,bn=1+anan.
已知等差数列an中,公差d>0,首项a1>0,bn=1/anan+1,数列bn的前n项和为Sn,则limSn=
若等比数列an满足anan+1=16n,则公比为( )
若Sn是公差不为0的等差数列{an}的前n项和,且S1,S2,S4成等比数列 设bn=3/anan+1,Tn是数列{bn
一道高中等差数列题设数列{an}是首项为1,公差为2的等差数列,其前n项和为Sn.设Cn=1/(anan+1),Tn=C
等差数列an=2n+3,求和:(1/a1a2)+(1/a2a3)+.+(1/anan+1)
等差数列{an}中,an=3n-1,则公差d为
an是首项为3,公差,公差为2的等差数列,则lim(1/a1a2+1/a2a3+……+1/a(n-1)an)=
,(苏2004)设无穷等差数列{an}的前n项和为sn.(Ⅰ)若首项a1=3/2,公差d=1,求满足 的