Fish Wang => YSITD: 也就是 2 ^ n 會等於 2 ^ (n - 1) + .... + 2 ^ 0 + 1 #5a90f83c22144b28ef4e3a1a

Fish Wang says to YSITD

也就是 2 ^ n 會等於 2 ^ (n - 1) + .... + 2 ^ 0 + 1

at Sat, Feb 24, 2018 1:29 PM