(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)-1
=1/2*(3-1)*(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)-1
=1/2(3^2-1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)-1
=1/2*(3^4-1)(3^4+1)(3^8+1)(3^16+1)-1
=1*2(3^8-1)(3^8+1)(3^16+1)-1
=1/2*(3^16-1)(3^16+1)-1
=1/2(3^32-1)-1
=1/2(3^32+1)
=3^32/2+1/2