Documentation/How Tos/Calc: FACTDOUBLE function

FACTDOUBLE

Returns the double factorial of a number.

This function is only available if the Analysis AddIn is installed.

Syntax:

FACTDOUBLE(number)

returns number!!, the double factorial of number, where number is an integer greater than or equal to zero.

For even numbers FACTDOUBLE(number) returns:

2*4*6*8* ... *number

For odd numbers FACTDOUBLE(number) returns:

1*3*5*7* ... *number

FACTDOUBLE(0) returns 1 by definition.

Example:

FACTDOUBLE(5)

returns 15.

FACTDOUBLE(6)

returns 48.

FACTDOUBLE(0)

returns 1.

Issues:

• This function currently appears in the AddIn category of the Function Wizard.