a1=1,a(n+1)=2an,a2+a4+a6+.+a2n=

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) 1.a1=1 an=a1+2a2+.(n-1)an-1求an2.an+a（n+1）=1/2,a1=1,求an 数列{an}中,an是整数,a1=1,a2=2,2a(n-1) 已知数列{an}满足a1=a,a2=b,a(n+1)=a(n+2)+an,求a2012 (a1+a2+.+an)^2=a1^2+a2^2+.+an^2+2(a1a2+a2a3+.+a(n-1)an) n>=2用数学归纳法证明 数学归纳法证明(a1+a2+.+an)^2=a1^2+a2^2+.+an^2+2(a1a2+a1a3+.+a(n-1)*an).(n大于等于2) (a1+a2+a3+.+an)^2=a1^2+a2^2+.+an^2+2(a1a2+a2a3+...+a(n-1)an) ;n≥2.求用数学归纳法证明 (1)数列{an}中,a1=1,a2=-3,a(n+1)=an+a(n+2),则a2005=____(2)已知数列｛an｝满足a1=1,a1×a2×a3…an=n^2,求an. 等比数列{an},Sn=2^n-1,则a1^2+a2^2+...+a^n=? a1=4 a2=2 an=4乘(1/2)的n- 1次方.求a.1*a2+a2*a3+.+an*a(n+1) 已知数列{an}满足a(n+2)=a(n+1)-an,a1=1,a2=2,求a2005 已知数列{an}满足,a1=1,a2=2,a(n+1)=a(n+2)+an,求a2011? 已知数列{an}满足a1=1,a2=3,a(n+2)=a(n+1)-an,求S2012 数列an中,a1=1,a2=4,a(n+2)=a(n+1)-an.求a2008 a1=3,a(n+1)=an^2求通项公式a1=1,a2=-3,a(n+1)=an+a(n+2)求a2004 写出下列数列{an}的前5项 a1=1,a(n+1)=an+3 a1=2,a(n+1)=2an a1=3,a2=6,a(n+2)=a(n+1)-an 设a1,a2,...,an都是正数,证明不等式(a1+a2+...+an)[1/(a1)+1/(a2)+...+1/(an)]>=n^2 已知数列{an}满足：a1=1,an=a1+2a2+3a3+``````+(n-1)a(n-1)(n大于等于2）,则通项公式an是什么?