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已知数列{an}的前n项和为Sn,且满足Sn=2an-n,(n∈N*)(Ⅰ)求a1,a2,...
试题详情
已知数列{a
n}的前n项和为S
n,且满足S
n=2a
n-n,(n∈N
*)
(Ⅰ)求a
1,a
2,a
3的值;
(Ⅱ)求数列{a
n}的通项公式;
(Ⅲ)若b
n=(2n+1)a
n+2n+1,数列{b
n}的前n项和为T
n,求满足不等式
≥128的最小n值.
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已知数列{an}的前n项和为Sn,且满足Sn=2an-n,(n∈N*)
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