an有界 2an≤an-1+an+1 证明极限an-an-1=0

an有界 2an≤an-1+an+1 证明极限an-an-1=0 有界数列2an≤an-1+an+1 证明极限an-an-1等于0 a1=3,an=2an-1+3 证{an+3}等比,并求an An, an 数列{an}满足an+1=2an 0≤an≤1/2 an+1=2an-1 1/2≤an an中 a1=1 an+1=3an+2 证an+1是等比数列 求an 已知数列{an},当n∈N*时都有an>0,且an^2≤an-a(n+1),证明an 数列an中,a1=3,an+1=an/2an+1,则an=? 在{an}中an>0 Sn=1/2（an+n/an）求an 实数列{an}满足an+2=|an+1|-an,是试判断{an}的周期性 数列{an}中,2an*an+1+2an+1-an=0,a1=1,an=? 数列｛an｝中,a1=1/2 3an*an-1+an-an-1=0,通项公式an 已知a1=2,an不等于0,且an+1-an=2an+1an,求an 已知等比数列{an}中有an+1-an=n×2^n且a1=1求an 周期性函数递推设数列｛an｝满足a1=a2=1,a3=2,且对任意正整数n都有an*an+1*an+2≠1,又an*an+1*an+2*an+3=an+an+1+an+2+an+3,求a1+a2+…a100 A1=1,An+1=3An/(3An+6) 证(1/An)+1等比 在数列{an}中,a1=1,a2=5,an+2=an+1-an (n∈N*), 则a100等于an+2=an+1-an,an+3=an+2-an+1, 两式相加可得an在数列{an}中,a1=1,a2=5,an+2=an+1-an (n∈N*), 则a100等于( )方法一: an+2=an+1-an,an+3=an+2-an+1, 两式相加