数列{an}满足a1+3?a2+32?a3+…+3n-1?an=,则an=
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A解析分析:由题干知a1+3?a2+32?a3+…+3n-1?an=,可知a1+3?a2+32?a3+…+3n-2?an-1=,两式相减即可得到an的表达式.解答:∵a1+3?a2+32?a3+…+3n-1?an=…①,∴a1+3?a2+32?a3+…+3n-2?an-1=…②由①-②可知,3n-1?an=-,∴an=?,故选A.点评:本题主要考查数列递推式的知识点,解答本题的关键是求出{an-1}满足的等式,此题难度不大,是比较基础的题.