设等差数列{an}满足a3=5,a10=-9.使得{an}的前n项和Sn最大的序号n=______.
设等差数列{an}满足a3=5,a10=-9,Sn是数列{an}的前n项和,则Sn的最大值为______.
设等差数列【An】满足A3=5,A10=-9,求通项公式,前n的和Sn及最大的序号n的值
设等差数列{an}的前n项和为Sn,已知a3=5,S3=9.
设数列{an}的前n项和为Sn满足2Sn=an+1-2n+1+1,n∈N*,且a1,a2+5,a3成等差数列.
已知等差数列{an}的前n项和Sn,a3+a8=5,则S10=______.
设数列{an}的前n项和为Sn,满足2Sn=an+1-2^n+1+1,且a1,a2+5.a3成等差数列
已知等差数列{an}满足:a3=7,a5+a7=26,{an}的前n项和为Sn.求an及Sn.
设等差数列{an}的前n项和sn,已知a3=12,s12>0.s13
已知{an}为等差数列,Sn为{an}的前n项和,n∈N*,若a3=16,S20=20,则S10值为______.
设等差数列{an}的前n项和为sn,已知a3=5,s3=9
设Sn是等差数列{an}的前n项和,若a5/a3=5/9,则S9/S5=:
已知等差数列{an}的前n项和Sn满足:Sn=n2+2n+a(n∈N*),则实数a=______.