(2+1)(2^2+1)(2^4+1)(2^8+1)(2^16+1)(2^32+1)+1
=[(2^2-1)/(2-1)]*[(2^4-1)/(2^2-1)]*[(2^8-1)/(2^4-1)]*[(2^16-1)/(2^8-1)]*[(2^32-1)/(2^16-1)]*[(2^64-1)/(2^32-1)]
=2^64-1+1
=2^64
2^1=2
2^2=4
2^3=8
2^4=16
2^5=32
2^6=64
2^7=128
末位数字规律:2,4,8,6,2,4,8,6
4个一个循环,因为64/4=16可以整除
所以末位数字是6