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问题: 帮忙求个数列通项

求{An}通项
(An+1)/An=n/2^n+1
A1=1

解答:


An/A(n-1)=(n-1)/2^n
.......
A2/A1 =1/2

相乘
An/A1 =(n-1)!/2^(1+2+....+n)
=(n-1)!/2^[n(n+1)/2]
An =(n-1)!/2^[n(n+1)/2]