已知递增等差数列{an}满足:a1=1,且a1,a2.a4成等比.(
已知递增等差数列{an}满足:a1=1,且a1,a2.a4成等比.(
等差数列{an}满足a1=1,且a1、a2、a4成等比数列,求an
已知等差数列(an)的公差为2,若a1,a3,a4成等比则a2=?
已知公差不为0的等差数列an的首项a1为a,且(1/a1),(1/a2),(1/a4)成等比
已知数列{an}是公差不为0的等差数列,a1=2,且.a2是a1、a4的等比中项,n∈N*.
已知递增的等差数列{an}满足a1=1,a
已知等比数列{an}满足a1=3,且4a1,2a2,a3成等差数列,则a3+a4+a5=( )
已知等比数列{An},a1=3,且4a1 2a2 a3成等差数列,则a3+a4+a5等于?
已知递增的等差数列{an}满足a1=1,a3=a2-4,则an=____.
设{an}为等差数列,且公差d为正数,已知a2+a3+a4=15,又a2,a3-1,a4成等比数列,求a1和d?
设{An}为等差数列,且公差d为正数,已知a2+a3+a4=15,又a2,a3-1,a4成等比数列,求a1和d
已知数列an是等比数列,且a1,a2,a4成等差数列,求数列an的公比