(1-1/2)(1+1/2)(1+1/2^2)(1+2^4)(1+2^8)(1+2^16)
=(1-1/2)(1+1/2)(1+1/2^2)(1+2^4)(1+2^8)(1+2^16)
=(1-1/2^2)(1+1/2^2)(1+1/2^4)(1+1/2^8)(1+1/2^16)
=(1-1/2^4)(1+1/2^4)(1+1/2^8)(1+1/2^16)
=(1-1/2^8)(1+1/2^8)(1+1/2^16)
=(1-1/2^16)(1+1/2^16)
=(1-1/2^32)
所以原式=(1-1/2^32)/(1-1/2)=2-1/2^31