Calculate 1 / (1 * 3) + 1 / (3 * 5) + 1 / (5 * 7) +... + 1 / (2n-1) * (2n-1) =?

Calculate 1 / (1 * 3) + 1 / (3 * 5) + 1 / (5 * 7) +... + 1 / (2n-1) * (2n-1) =?

=1/2*[1-1/3+1/3-1/5+1/5-1/7+…… +1/(2n-1)-1/(2n+1)]
=1/2*[1-1/(2n+1)]
=n/(2n+1)

1, 3, 7, 13, (), 31, ()

22.44

If a square has a side length of 1, make another square with the diagonal of the square as the side length, and make a new square with the diagonal of the second square as the side length, then the side length of the nth square is______ ．

It can be concluded from the meaning of the title: the side length of the first square is: 1 = (2) 0, the side length of the second square is: 2 = (2) 1, the side length of the third square is: 2 = (2) 2, the side length of the Fourth Square is: 22 = (2) 3, so the side length of the nth square is: (2) n-1