Big Oh time complexity for alpha(n)

big-o, time-complexity

Solution

It appears to be a reference to the inverse Ackermann function, written as `α(n)`

From wikipedia:

This inverse appears in the time complexity of some algorithms, such as the disjoint-set data structure and Chazelle's algorithm for minimum spanning trees.

Problem

What does O(alpha(n)) mean? I recently stumbled upon 2048 but in terms of run times and one of the blocks had that. Thanks!

Original source