=(2-1)(2+1)(2^2+1)(2^4+1)(2^8+1)+......+(2^2n +1)
=(2^2-1)(2^2+1)(2^4+1)(2^8+1)+......+(2^2n +1)
=(2^4-1)(2^4+1)(2^8+1)+......+(2^2n +1)
=....
=2^4n-1
原始式子最前面添加个2-1然后用平方差公式得到结果为2^4n_1毕
(2+1)(2^2+1)……(2^2n+1)
=(2-1)(2+1)(2^2+1)……(2^2n+1)/(2-1)
=(2^2-1)(2^2+1)……(2^2n+1)/1
=(2^4-1)(2^4+1)……(2^2n+1)
=……
=2^4n-1