（1+1/2）（1+1/2的平方）（1+1/2的4次方）（1+1/2的8次方）+1/2的15次方

(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15方
=2*(1-1/2)(1+1/2)(1+1/2^2)(1+1/2^4)(1+1/2^8)+1/2^15
=2*(1-1/2^2)(1+1/2^2)(1+1/2^4)(1+1/2^8)+1/2^15
=2*(1-1/2^4)(1+1/2^4)(1+1/2^8)+1/2^15
=2*(1-1/2^8)(1+1/2^8)+1/2^15
=2(1-1/2^16)+1/2^15
=2-1/2^15+1/2^15
=2