Folding a piece of paper once is 2 pages, folding it twice is 2×2=4 pages, folding it three times is 2×2×2=8 pages ... and folding it n times is the multiplication of n twos, which is the n power of 2.

The remainder of "one foot vertebra, half a day, is inexhaustible" is: 1/2, 1/4, 1/8, ... that is, the n power of 1/2.