..  _fact:

FACT
====

+----------+-------------------------------------------------------------------+
| Syntax   |  FACT(n) where n=0..300                                           |
+----------+-------------------------------------------------------------------+
| Location |  Math Package, FACT                                               |
+----------+-------------------------------------------------------------------+

The FACT function takes a non-negative integer n up to 300 and
returns the factorial of the number, calculated as the product:
1\*2\*3\*...\*n

**Example**

n elements can be combined in FACT(n) different ways, eg. take the three
first letters, the FACT(3)=6 permutations of A, B and C are:

1. ABC
2. ACB
3. BAC
4. BCA
5. CAB
6. CBA

**CROSS-REFERENCE**

:ref:`binom`