(x-1/2)(2x+1)(2x^2+1/2)(4x^4+1/4)(16x^6+1/16)/(256x^16-1/256)
=(2x^2-1/2)(2x^2+1/2)(4x^4+1/4)(16x^6+1/16)/(256x^16-1/256)
=(4x^4-1/4)(4x^4+1/4)(16x^6+1/16)/(256x^16-1/256)
=(16x^6-1/16)(16x^6+1/16)/(256x^16-1/256)
=(256x^16-1/256)/(256x^16-1/256)
=1