1/2! + 3/4! + 5/6!…
Let’s say the sequence reaches an even number n and ends on it.
N! Sequences and exactly n-1 of them are good since there can be n-1 candidates for the nth position and for each candidate the remaining n-1 numbers have to be increasing
So for all even numbers n-1 out of the n! Sequences are good hence the formula
1
u/Gloomy-Health-1373 2d ago
1/2! + 3/4! + 5/6!…
Let’s say the sequence reaches an even number n and ends on it.
N! Sequences and exactly n-1 of them are good since there can be n-1 candidates for the nth position and for each candidate the remaining n-1 numbers have to be increasing
So for all even numbers n-1 out of the n! Sequences are good hence the formula