FACTDOUBLE ( n )

Description: Computes the double factorial of n.

Mathematical Formula:

If n is even:

If n is odd:

Arguments:

Name	Type	Description
n	number	The non-negative value whose double factorial is to be computed. n is truncated to an integer.

Return Type and Value: number – The double factorial of n.

However, if

• n is negative, #NUM! is returned.

• n is too large for the result to be representable, #NUM! is returned.

[Example:

FACTDOUBLE(5) results in 15
FACTDOUBLE (3.5) results in 3
FACTDOUBLE (0) results in 1

end example]