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
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
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
已知等差数列﹛an﹜的前n项和为Sn,且a3=5,S6=36,bn=2an×2的an次方
已知{an}为等差数列,前n项和为Sn,S5=S6且a3=-6,(1)求数列{an}的通项公式
已知等差数列{An}的前n项和为Sn,且A3=5,S6=36.
已知等差数列{An}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=10,S6=72.若bn=12
已知等差数列{an},Sn是其前n项和,满足:a3=5,S6=36且an=2n-1 记bn=1/(an·an+1),Tn
求证等差数列!已知数列an的各项均为正数,前n项和为Sn,且满足2Sn=a∧2n+n-4
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.
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