已知数列{an}满足a1+2·a2+2^2·a3+……+2^(n-1)·an=n/2,则an=
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
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已知数列{an}满足:a1+a2+a3+…+an=n-an 求证{an-1}为等比数列 令bn=(2-n)(an-1)求
已知数列{an}满足a1+a2+a3+…+nan=n(n+1)(n+2),则{an}的通项公式为an=
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+a2+a3+.+an=n^2,求数列{an}的通项an.
已知数列{an}满足a1=1,an=a1+2a2+3a3.+(n-1)an-1 (n>=2),则{an}的通项是什么
已知数列{an}满足a1*a2*a3···a(n-1)*an=n^2,则a10-a4=
数列an满足a1+2a2+3a3+...+nan=(n+1)(n+2) 求通项an