已知数列{an}满足a1+a2+a3+……+an=2n²-3nº则a5=?
已知数列{an}满足a1+a2+a3+……+an=2n²-3nº则a5=?
1.数列{an}满足a1+a2+……+an=[4-(-2)^n]/3,n∈N*,则1/a1+1/a3+1/a5+……1/
已知数列{an}满足a1+2a2+3a3+…+nan=n(n+1)(n+2),则a1+a2+a3+…+an=多少?
数列{an}满足:1/a1+2/a2+3/a3+…+n/an=2n
已知数列an满足a1+3a2+3²a3+……+3的n-1次方an=n/2,则an=
已知数列(an)满足a1=1,an+1=2an/an+2(n∈N*) 求a2,a3,a4,a5 猜想数列(an)的通项公
已知数列{an}满足a1=1,an=a1 +1/2a2 +1/3a3 … +1/(n-1)a(n-1),(n>1,n∈N
已经数列{an}.a1+a2+a3+…+an=2n^2-3n+1.求a4+a5+…+a10
已知数列{an}中满足a1=1,a(n+1)=2an+1 (n∈N*),证明a1/a2+a2/a3+…+an/a(n+1
已知数列an满足a1=1,an+1={2n ,n为奇数 an+2 ,n为偶数 ,且a1+a3+a5+……+a2k-
已知数列{an}:a1=1,当n大于等于2时,a1*a2*a3*…*an=n^2,求a3+a5的值
已知数列an满足a1+2a2+3a3+……+nan=2^n,求an