高—:2Sn=a(n+1)(这是数列第n+1项)-2^n+1十1,且a1,a2+5,a3成等差,求通项an.
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=a(n+1)-2^(n+1)+1,n属于n*.且a1,a2+5,a3成等差数
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
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,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an的前n项和为Sn=n^2+2n,求和:1/(a1*a2)+1/(a2*a3)+...+1/(an*a(n+1
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,已知a1=1,a2=6,a3=11,且(5n-8)S(n+1)-(5n+2)Sn=A*n
设数列{an}的前n项和为Sn,已知a1=1 a2=6 a3=11 且(5n-8)Sn+1-(5n+2)Sn =A*n+
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.
数列{an}的前n项和为Sn=nPan(n属于N+),且a1不等于a2(1)求常数P的值(2)证明:数列{an}是等差数
已知数列{an}的前n项和sn=n^2+2n+3,求和1/a1+a2+1/a2+a3+1/a3+a4+.+1/an+an