# factorial

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## 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 integerCollins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

The following article is from

*The Great Soviet Encyclopedia*(1979). It might be outdated or ideologically biased.## Factorial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*.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

## factorial

[fak′tȯr·ē·əl] (mathematics)

The product of all positive integers less than or equal to

*n;*written*n*!; by convention 0! = 1.McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

## 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.

This article is provided by FOLDOC - Free Online Dictionary of Computing (

**foldoc.org**)## factorial

The number of sequences that can exist with a set of items, derived by multiplying the number of items by the next lowest number until 1 is reached. For example, three items have six sequences (3x2x1=6): 123, 132, 231, 213, 312 and 321. See factor and IFP.Copyright © 1981-2019 by

**The Computer Language Company Inc**. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.