已知数列{an}满足2a(n+1)=an+a(n+2)(n∈N*),它的前n项和为sn,且a3=5,s6=36,
已知数列{an}满足2a(n+1)=an+a(n+2)(n∈N*),它的前n项和为sn,且a3=5,s6=36,
已知数列{an}满足2an+1=an+an+2(n∈N*),它的前n项和为Sn,且a3=-6,S6=-30.求数列{an
已知数列{an}满足2an+1=an+an+2(n∈N*),它的前n项和为Sn,且a3=10,S6=72.若bn=12
已知数列{an}满足2an+1=an+an+2(n=1,2,3,…),它的前n项和为Sn,且a3=5,S6=36.
已知数列{an}满足2a(n+1)(下脚标)=an+a(n+2)(下脚标)(n∈N+)它的前n项和为Sn,且a3=10,
已知等差数列{An}的前n项和为Sn,且A3=6,S6=42.且满足A(n+2)=2A(n+1)-An
设数列an的前n项和为sn,满足2Sn=a(n+1)-2^(n+1)+1,n∈N,且a1,a2+5,a3成等差数列
已知数列{a(n)}Sn是其前n项的和,且满足3an=2Sn+n(n∈N※)
设数列{an}的前n项和为sn,满足2sn=a(n+1)-2^(n+1)+1,n属于n*.且a1,a2+5,a3成等差数
已知数列an的前n项和为Sn=n^2+2n,求和:1/(a1*a2)+1/(a2*a3)+...+1/(an*a(n+1
已知数列an的前n项和为sn,且sn+an=1/2(n2+5n+2)(2属于n*) 计算a1 a2 a3 a4
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