设an=根号n+根号(n+1),求Sn=a1+a2+a3+...+an
设an=根号n+根号(n+1),求Sn=a1+a2+a3+...+an
an=1/[根号下(n+1)+根号下(n)],则a1+a2+a3+.+a10=
设数列{an}的前n项和为Sn,并且满足2Sn=an²+n,an>0.(1)求a1,a2,a3.(2)猜想{a
设数列{an}满足Sn=n^2+1,Pn=1/a1.a2+1/a2.a3+.+1/an.an+1,求n=?
设各项均为正数的数列{an}的前n项和为Sn,已知2a2=a1+a3,数列{根号Sn}是公差为2的等差数列.(1)求数列
等差数列{an}中,a1+a2+a3=21,an-2+an-1+an=57,Sn=520,求n.
在数列an中 a1=1 a(n+1)乘根号下an=8 1求a2 a3 2 设bn=lo
在正项数列an中Sn=1/(根号a1+根号a2)+1/(根号a2+根号a3)+...+1/(根号an+根号an+1)
已知数列{an}满足A1=0,A(N+1)=AN减去根号三/根号三AN加1.求A2,A3,A4,A5,A6
设数列{an}满足a1=2,a(n+1)=an+1/an(1)求a2,a3,a4(2)比较an与根号(2n+1)的大小,
在等差数列中,a2+a3+a4=15,a5=9,设bn=(根号三)1+an,求数列bn的前n项和sn
设数列{an}的前n项和为sn,已知a1+2a2+3a3+…+nan=(n-1)Sn+2n(n∈N*)