a1=1/2,(n,2an+1 - an)在直线y=x上,1、令bn=an+1 - an -1,求证bn为等比2、求an

数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an an=a1+(n-1)d 和Sn=n(a1+an)/2中an是什么意思? an=a1+(n-1)d 和Sn=n(a1+an)/2中an是什么 数列{an}满足a1=1 an+1=2n+1an/an+2n 数列｛an},a1=1,an+1=2an-n^2+3n,求｛an｝. 数列{an}中,a1=1,an+1/an=n/n+2,求an a1=1,Sn=n^2an,求an a1=1/2,an+1=an/an+2,求n/an的sn 数列an集合中,a1=2,an+1=an+(2n+1),求an. an+1 ,n+1是下表 ,an+1=an^3 a1=2 ,求an 设数列{an}中,a1=2,an+1=an+n+1,则通项an=? 数列{an}中,a1=35,an+1-an=2n-1,求an 已知数列an,a1=1 an+1-an=2的n次幂求an 数列｛an｝满足a1=1,且an=an-1+3n-2,求an 数列{an},a1=2,an+1(下标)=an下标+n+1 求通项an下标 在数列an中,a1=2 an+1=an+3n则an= 已知数列{an}满足an+1=2an+3.5^n,a1=6.求an 已知{an}满足a1=1.an=3*n+2An-1,求an