n-factorial
nounUK /ɛn fækˈtɔː.ri.əl/
US /ɛn fækˈtɔːr.i.əl/
The product of all whole numbers from 1 up to n, written with an exclamation mark.
The n-factorial of 5, written 5!, equals 120.
OTHER MEANINGS
2. A mathematical function denoted by an exclamation mark that multiplies a number by every smaller positive integer.
She computed the factorial of 6 to solve the counting problem.
3. In combinatorics, the number of ways to arrange n distinct objects in a row.
The n-factorial counts the orderings of n different books on a shelf.
4. A recursive expression where n! equals n times (n−1)!.
Using the recursive rule, 4! is 4 times 3!, which is 24.