3(2^2+1)*(2^4+1)*(2^8+1)-2^16
=(2^2-1)(2^2+1)(2^4+1)(2^8+1)-2^(16)
=(2^4-1)（2^4+1）(2^8+1)-2^16
=(2^8-1)(2^8+2)-2^16
=2^16-1-2^16
=-1