(2+1)(2^2+1)(2^4+1)... ...(2^128+1)=

(2+1)(2^2+1)(2^4+1)... ...(2^128+1)
=(2-1)(2+1)(2^2+1)(2^4+1)... ...(2^128+1)
=(2^-1)(2^2+1)(2^4+1)... ...(2^128+1)
=(2^4-1)(2^4+1)... ...(2^128+1)
=2^256-1

=(2-1)(2+1)(2^2+1)(2^4+1)... ...(2^128+1)
=2^256-1
平方差公式

在前面乘上2-1这个式子会产生类似多米诺骨牌的效应，不断的运用平方差公式，得到最后结果是
2^256-1