What is epifactorial?

Epifactorial is a concept primarily used in mathematics and combinatorics, referring to a specific type of factorial operation that is applied iteratively. It involves taking the factorial of a number and then applying the factorial operation again to the result, and this process can be repeated multiple times. The notation and precise definitions can vary, but it generally emphasizes the recursive nature of the factorial function. Understanding epifactorials can be useful in advanced combinatorial problems and discussions about growth rates in mathematics.