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. A B C   
2. A C B   
3. B A C   
4. B C A   
5. C A B   
6. C B A 

CROSS-REFERENCE: 
BINOM
