已知等差数列{an}满足a2=3,Sn-Sn-3=51(n>3),Sn=100,则n的值为( )
已知等差数列{an}满足a2=3,Sn-Sn-3=51(n>3),Sn=100,则n的值为( )
已知等差数列{an}的前N项和为Sn,a1=-2/3,满足Sn+1/Sn+2=an(n大于等于2)
已知等差数列{an}的前N项和为Sn,a1=-2/3,满足Sn+1/Sn+2=an(n大于等于2),
已知数列{an}的首相a1=1,a2=3,前n项和为Sn,且Sn+1(下标)、Sn、Sn-1(下标)(n≥2)满足(Sn
已知等差数列{an}的前N项和为Sn,a1=-2/3,满足Sn+1/Sn+2=an(n大于等于2) 求Sn 别用数学归纳
1.已知等差数列满足a2=3,S-S(n-3)=51(n>3),Sn=100,则n的值为_
已知公差大于零的等差数列an前n项和为Sn,且满足a3a4=-3,a2+a5=2.(1)求通项a
等差数列:已知两个等差数列(An),(Bn),它们的前n项和分别为Sn,Sn',若Sn/Sn'=2n+3/3n-1求a9
已知数列{an}的前n项和为sn,a1=3,满足sn=6-2a n+1(n∈N*) ⑴ 求a2,a3,a4的值; ⑵ 猜
已知数列{an}的前n项和为Sn,且满足Sn=Sn-1/2Sn-1 +1,a1=2,求证{1/Sn}是等差数列
已知数列{an}的前n项和为Sn,Sn=(an-1)/3 (n∈N)
设数列[an}的前n项和为Sn,已知a1=1且满足3Sn的平方=an(3Sn-1),1求{1/Sn}为等差数列 1.求{