Question

（2+1）（22+1）（24+1）（28+1）••••••（264+1）=?

Answer 1

(2+1)(2^2+1)(2^4+1)(2^8+1)...(2^64+1)

=(2-1)(2+1)(2^2+1)(2^4+1)(2^8+1)...(2^64+1)

=(2^2-1)(2^2+1)(2^4+1)(2^8+1)...(2^64+1)

=(2^4-1)(2^4+1)(2^8+1)...(2^64+1)

.

=(2^64-1)(2^64+1)

=2^128-1