设数列an满足a1=a2=1，a3=2，且对任意正整数n都有相邻四项之和等于它们的积，相邻的三项之和不等于1，求a1+a

设函数f(x)=1/x,数列an满足：a1=a不等于0,且对于任意的正整数n都有an+1=f(an^2),则a1*a2… 在数列{an}中,a1=2010,且对任意正整数,都有a(n+2)=a(n+1)-an,则a2+a3+a4+……+a20 已知数列{An}的前n项和为Sn,且满足A1=2,AnAn+1=4Sn对任意n属于正整数都成立..求A2,A3,A4. 设数列{an}对所有正整数n都满足：a1+2a2+2^2a3+…+2^(n-1)an=8-5n,求数列{an}的前n项和 设数列an满足a1=a2=1,a3=2,且对正整数n都有an·an+1·an+2·an+3=an+an+1+an+2+a 设数列an的前n项之和为sn 且满足an=2-sn (1)求a1,a2,a3,a4的值并写出通项公式. 已知等差数列an的首项a1为a,设数列的前n项和为Sn,且对任意正整数n都有a2n/an=4n-1/2n-1,求数列的通 设数列{an}满足a1+3 a2+3^2 a3+……+3^n-1 an=n/3,a属于N* 求数列{an}的通项 设数列An对所有自然数n,都满足a1+2a2+2^2a3+…+2^n-1an=8-5n,求数列a n 的通项公式,求具体 设数列{An}满足A1+3A2+3^2*A3+...+3^(n-1)*An=n/3,a属于正整数. 已知等比数列{an}的通项公式为a=3^(n-1),设数列{bn}满足对任意自然数N都有(b1/a1)+(b2/a2)+ 数列{an}中,a1=1,对所有的n大于等于2,都有a1●a2●a3…an=n^2,求a5