乘一个(2一l)变为:(2一l)(2十1)(2^2十1)()…等于(2^2一I)(2^2十1)()…等于(2^4一1)(2^4十)()…最后等于(2^64一l)(2^64十I)等于2^128一l
(2-1)(2+1)(2^2+1)(2^4+1)(2^8+1)…(2^64+1)/(2-1)=(2^2-1)(2^2+1)(2^4+1)(2^8+1)…(2^64+1)/(2-1).....=(2^128-1)/(2-1)=2^128-1