设a1=5,a(n+1)=√（4+an),求该数列的极限,

设a1=5,a(n+1)=√（4+an),求该数列的极限, 设数列﹛an﹜中,a1+4,an=3a(n-1)+2n-1,求通项an 设数列{an},a1=2,a（n+1）=an+In·（1+1/n）,求an 设数列an满足a1=1,a2=4,a3=9,an=a(n-1)+a(n-2)-a(n-3).则a2011= 设数列an满足a1=2,a(n+1)=3an+2^(n-1),求an2,设数列an满足a1=2,a(n+1)=3an+2n,求an 如下 设递增数列{an}满足a1=1,4an+1=5an+√9an^2+16（n∈N+）设递增数列{an}满足a1=1,4an+1=5an+√9an^2+16（n∈N+）(1)求数列{an}的通项公式(2)证明：1/a1+1/a2+1/a3+……+1/an 设数列{an}满足a1=2,an+1=an+1/an,(n∈N).令bn=an/根号下n,判断bn与bn+1的大小a1=2a(n+1)=an+(1/an)a(n+1) > anb(n+1)-bn = a(n+1)/ √(n+1) - an/√n> an/ √(n+1) - an/√n＜0b(n+1) ＜ bn 设数列{an},a1=3,a(n+1)=3an -2 (1)求证:数列{an-1}为等比数列 设数列{an}中,a1=2,an+1=an+n+1,则通项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 设数列{an}前n项和为sn,已知a1=1,s(n+1)=4an+2 1.设bn=a（n+1）-2an,证明{bn}是等比数列 2.{an}通项 设数列{an}满足a1=2,a(n+1)=an+1/an,(n∈N+) 1、求a2,a3 2、证明an>√(2n+1)对一切正整数n成立 数列 设数列{an},a1>0,an=根号[3a(n-1)+4],n-1是下标,证明：|an-4|=2)；liman=4设数列{an},a1>0,an=根号[3a(n-1)+4],n-1是下标,（n>=2）,证明：|an-4|=2)；liman=4 1.a1=3 且 a（n+1）=an+5ana（n+1）2.a1=1 且 a（n+1）=an+2n+13.a1=1 且 a（n+1）=an+1/4n^2-14.a1=1 an=n+1/n*a（n+1）求各题的an 设数列｛an｝中,a1=1且(2n+1)an=(2n-3)a(n-1),(n大于等于2）,求{an},sn 设Sn是数列{an}的前n项和,a1=a,且Sn^2=3n^2an+S(n-1)^2,证明数列{a(n+2)-an}是常数数列设Sn是数列{an}的前n项和,a1=a,且Sn^2=3n^2an+S(n-1)^2,an≠0,n=2,3,4……证明数列{a(n+2)-an}（n≥2）是常数数列 1.已知数列{an}中,a1=1,an=3^(n-1)+a(n-1)(n>=2),求通项公式an2.已知数列{an}满足a1=2,an=a^2(n-1)[括号内是足标](n>=2),求通项公式an3.已知数列{an}的首项a1=5,且an=a1+a2...+a(n-1)(n>=2)求通项公式an4.设{an}是首项为 设数列{an}的首项a1=a(a不等于1/4),且a(n+1)=1/2*an,n为偶数,a(n+1)=an+（1/4）,n为奇数,求a2,a3