# factorial

(redirected from*Factorial function*)

Also found in: Dictionary, Thesaurus, Medical.

## factorial

*Maths*

the product of all the positive integers from one up to and including a given integer. Factorial zero is assigned the value of one:

*factorial four is 1 × 2 × 3 × 4*. Symbol:*n*!, where*n*is the given integer## Factorial

The factorial of a given natural number *n* is the product of all the natural numbers less than or equal to *n*. The factorial of *n* is denoted usually by *n!* Thus,

*n!* = 1 × 2 × ... × *n*

For large *n* an approximate expression for n! is given by Stirling’s formula. The number of permutations of *n* things taken all at a time is the factorial of *n*.

## factorial

[fak′tȯr·ē·əl] (mathematics)

The product of all positive integers less than or equal to

*n;*written*n*!; by convention 0! = 1.## factorial

(mathematics)The mathematical function that takes a
natural number, N, and returns the product of N and all
smaller positive integers. This is written

N! = N * (N-1) * (N-2) * ... * 1.

The factorial of zero is one because it is an empty product.

Factorial can be defined recursively as

0! = 1 N! = N * (N-1)! , N > 0

The gamma function is the equivalent for real numbers.

N! = N * (N-1) * (N-2) * ... * 1.

The factorial of zero is one because it is an empty product.

Factorial can be defined recursively as

0! = 1 N! = N * (N-1)! , N > 0

The gamma function is the equivalent for real numbers.