已知等差数列{an}的首项a1及公差d都是整数,前n项和为Sn(n∈N*).若a1>1,a4>3,S3≤9,则通项公式a
已知等差数列{an}的首项a1及公差d都是整数,前n项和为Sn(n∈N*).若a1>1,a4>3,S3≤9,则通项公式a
等差数列{an}的首项a1及公差d都是整数,前n项和Sn
设等差数列{an}的首项及公差均是正整数,前n项和为sn,且a1>1,a4>6,s3≤12,则a2013=?
已知等差数列{an}的公差d>0,设{an}的前n项和为Sn,a1=1,S2•S3=36.
已知等差数列{an}前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13,成等比数列,求{an}通项公式.
已知等差数列{an}的前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13成等比数列.
设等差数列{an}的首项及公差均是正整数,前n项和为Sn,且a1>1,a4>6,S3≤12,则a2015=______.
已知等差数列{an}前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13,成等比数列 设{bn/an}是首
已知公差不为0的等差数列{an}的前n项和为Sn,S3=a4+6,且a1,a4,a13成等比数列.
已知等差数列{an}前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13,成等比数列 (2)若从数列
高一数学. 已知等差数列{an}的前n项和胃Sn,公差d≠0,且S3+S5=50,a1,a4,a13成等比数列.
设等差数列{an}的首项a1及公差d都为整数,前n项和为sn.若a1>=6,a11>0,s14