Let y₀, y₁, y₂,... be a sequence of random unsigned 32 bit integers
(i.e. 0 ≤ y_i < 2³², every value equally likely).

For the sequence x_i the following recursion is given:

• x₀ = 0 and
• x_i = x_i-1 | y_i-1, for i > 0. ( | is the bitwise-OR operator)

It can be seen that eventually there will be an index N such that x_i = 2³² -1 (a bit-pattern of all ones) for all i ≥ N.

Find the expected value of N.
Give your answer rounded to 10 digits after the decimal point.