(2+1)(4+1)(16+1).(2* 2*2.*2+1)
=(2-1)(2+1)(4+1)(16+1).(2* 2*2.*2+1)
=(4-1)(4+1)(16+1).(2* 2*2.*2+1)
=(16-1)(16+1).(2* 2*2.*2+1)
=……
=2的64次方-1
(2+1)(4+1)(16+1).(2* 2*2.*2+1)
=(2-1)(2+1)(4+1)(16+1).(2* 2*2.*2+1)
=(4-1)(4+1)(16+1).(2* 2*2.*2+1)
=(16-1)(16+1).(2* 2*2.*2+1)
=……
=2的64次方-1