化簡方法是乘以一個2^2-1,再除以一個2^2-1,利用平方差公式化簡
(2^2+1)(2^4+1)(2^8+1)(2^16+1)(2^32+1)
=[(2^2-1)(2^2+1)](2^4+1)(2^8+1)(2^16+1)(2^32+1)/(2^2-1)
=[(2^4-1)(2^4+1)](2^8+1)(2^16+1)(2^32+1)/(2^2-1)
=[(2^8-1)(2^8+1)](2^16+1)(2^32+1)/(2^2-1)
=[(2^16-1)(2^16+1)](2^32+1)/(2^2-1)
=[(2^32-1)(2^32+1)]/(2^2-1)
=(2^64-1)/(2^2-1)
=1/3(2^64-1)
2^64很大的數(shù) ,到上一步應該可以了