(1+2分之1)(1+2的平方分之1)(1+2的四次方分之)(1+2的八次方分之1)(1+2的16次方分之1)
=2*(1-1/2)(1+1/2)(1+1/2^2)(1+1/2^4)(1+1/2^8)(1+1/2^16)
=2*(1-1/2^2)(1+1/2^2)(1+1/2^4)(1+1/2^8)(1+1/2^16)
=2*(1-1/2^4)(1+1/2^4)(1+1/2^8)(1+1/2^16)
=2*(1-1/2^8)(1+1/2^8)(1+1/2^16)
=2(1-1/2^16)(1+1/2^16)
=2(1-1/2^32)
=2-1/2^31