2(3+1)(3^2+1)(3^4+1)...(3^16+1)+1
=(3-1)(3+1)(3^2+1)(3^4+1)...(3^16+1)+1
=(3^2-1)(3^2+1)(3^4+1)…(3^16+1)+1
=(3^4-1)(3^4+1)……(3^16+1)+1
……
=(3^16-1)(3^16+1)
=3^32-1+1
=3^32
=(3-1)(3+1)(3^2+1)(3^4+1)...(3^16+1)+1
=3^32-1+1
=3^32
因为2=3-1 用平方差公式
2(3+1)(3^2+1)(3^4+1)...(3^16+1)+1
=﹙3-1﹚(3+1)(3^2+1)(3^4+1)...(3^16+1)+1
=3^32-1+1
=3^32
连续应用平方差公式。