设数列{a
n}满足:
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231554441718430/SYS201311012315544417184018_ST/0.png)
,且a
n-1=3a
n-1(n∈N
*,n≥2).
(1)求数列{a
n}的通项a
n;
(2)求{a
n}的前n项和S
n.
考点分析:
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