原式=(2-1)(2+1)(2^2+1)(2^4+1)……(2^2n+1)+1 =(2^2-1)(2^2+1)(2^4+1)……(2^2n+1)+1 =(2^4-1)(2^4+1)……(2^2n+1)+1 =…… =(2^2n-1)(2^2n+1)+1 =2^4n-1+1 =2^4n
