设等比数列{an}满足:a1=13,a2+a3=427,且an>0.
设{an}为等比数列,Tn=a1+2a2+…+(n-1)an-1+nan,已知an>0,a1=1,a2+a3=6.
已知等比数列{an}满足2a1+a3=3a2,且a3+2是a2,a4的等差中项
等比数列{an}满足a1+a2=3,a2+a3=6,则a7=______.
等比数列an满足 lim(a1+a2+a3+...+an)=1/2 求a1取值范围
若等比数列{an}满足a1+a2=3,a3+a4=12,则a1+a2+a3+……+an=
在等比数列{an}中,an>0且a2=1-a1,且a2=1-a1,a4=9-a3,则a4+a5的值是多少?
设{an}是公比为正数的等比数列a1=2,a3=a2+4.
已知等比数列(an)满足2a1+a3=3a2且a3+2是a2,a4的等差中项 求数列(an)的通项公式?
数列an满足n ∈ N*,an > 0 且a1^3 + a2^3 + a3^3 + ...+ an^3 = (a1 +
1.已知单调递增的等比数列{an}满足a1+a2+a3=39,且a2+6是a1,a3的等差中项.
已知两个等比数列{an},{bn},满足a1=a(a>0),b1-a1=1,b2-a2=2,b3-a3=3.
在等比数列{an}中,an>0且a1+a2=1,a3+a4=9,则a5+a6=______.