设数列[an}的前n项和为Sn,a1=a ,a2=p(p>0),Sn=n(an-a1)/2
设数列[an}的前n项和为Sn,a1=a ,a2=p(p>0),Sn=n(an-a1)/2
设数列{an}的前n项和为Sn,并且满足2Sn=an²+n,an>0.(1)求a1,a2,a3.(2)猜想{a
数列{an}前n项和Sn=npa[n](n是正整数),且a1不等于a2,(1)求p的值(2)证明{an}为等差数列
设数列{an}的前n项和为sn,已知a1+2a2+3a3+…+nan=(n-1)Sn+2n(n∈N*)
设数列an的前n项和为Sn,a1=1,an=(Sn/n)+2(n-1)(n∈N*) 求证:数列an为等差数列,
设数列{an}的前n项和为Sn,已知a1=a,an+1=Sn
设数列an的前n项和为Sn,满足2Sn=an-2∧n+1 +1 ,且a1,a2+5,a3成等差
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
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
设数列{an}的前n项和为Sn=2n²{bn}为等比数列,且a1=b1,b2(a2-a1)=b1
1.设数列{An}的前n项和为Sn=2n^2,{bn}为等比数列,且A1=b1,b2(A2-A1)
设数列{an}的前n项和为Sn,a1=10,a(n+1)=9Sn+10