数列{an}满足an+1+(-1)^nan=2n-1,则{an}的前40项和为________.

若数列{An}满足A1=2,nA(n+1)-(n+1)An=2,则数列{An}的通项公式A后面的n都是下标 数列an满足na(n+1)=(n+2)an,a1=1,求数列an的通项公式用累乘法jie 一道高二数列题已知数列{an}满足a1=2,an+1=2an/an+2 问：数列1/na是否是等差数列?为什么.并求an过程详细呀 已知数列{an}满足a1=1 an+1=an/(3an+1) 则球an 设数列{an},{bn}满足a1=1/2,2na(n+1)=(n+1)an,且{bn}=ln(1+an)+1/2an^2,求a2,a3,a4,并求数列an的通项公式 已知数列｛an｝满足na(n+1)=2(n+1)an,a1=1,求证｛an/n｝为等比数列(前一个n+1为下标) 数列{an}满足an=p/(pn+1-p)(0 数列{an}满足a1=1 an+1=2n+1an/an+2n 已知数列{an}满足an+1=an+n,a1等于1,则an=? 数列｛an｝满足a1=1,且an=an-1+3n-2,求an 数列an满足a1=2,an+1=4an+9,则an=? 已知数列{an}满足an+1=2an+3.5^n,a1=6.求an 数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an 数列an满足a1=2,an+1=an²求an 数列an满足a1=2,an+1=an²求an 数列[An]满足An+1-An+3=0,且A1=-5.求An. 已知数列{an}中满足(An+1-An)(An+1+An)=16,且a1=1,an 已知数列｛an｝满足na（n+1下角标）=2（n+1）an（n为N*）,a1=1.（1）求证：｛an除以n｝为等比数列（2）求数列｛an｝的通项公式