已知等差数列an中,an不等于0,an-an+1的平方+an+2=0,若S2k-1=38,则正整数k=?
已知a1=2,an不等于0,且an+1-an=2an+1an,求an
在等差数列an中,a1=2,3an+1-an=0,求an
若数列{An}满足An+1=An^2,则称数列{An}为“平方递推数列”,已知数列{an}中,a1=9,点(an,an+
已知等差数列{an}中,a1=2.an+1=an+3分之an 求an
已知数列an中,a1=1,an+1=2an/an+2(n属于正整数),求通项公式an?
已知数列{an}中,an>0且对任意正整数n有Sn=1/2(an+1/an),则通项公式an=
已知a1=1,2an+1*an+3an+1+an+2=0 求证{1/an+1}为等差数列(2)求an
{an}为等差数列,an不等于0,d为公差,求证:1/(a1a2)+1/(a2a3)+...+1/(an-1*an)=(
在数列{an}中,an>0,2√Sn=an+1,n∈正整数,
等比数列an中,an>0,q不等于1,若a3、a5,a6成等差数列,则q=?
已知{an}中,an>0,Sn是{an}的前n项和,且an+1/an=2Sn,求an.
已知等差数列{an}满足an+1=an²-nan+1,则an=______.