因为2^(n-1)An=A(n-1)
所以An/A(n-1)=2^(n-1)
所以An = (An/An-1)*(An-1/An-2)*(An-2/An-3)*…*(A2/A1)* A1
= 1/(2^n-1)*1/(2^n-2)*1/()2^n-3 … 1/2^1 * 1
= 1/(2^n-1*2^n-2*2^n-3 … 2^1)
= 1/2^(1+2+3+…+n-1)
= 1/2^[n(n-1)/2]
所以,最后An = 1/2^[n(n-1)/2] （n属于正整数）
上述中n-1 n-2等均为上标和下标.