FACTDOUBLE

Returns the double factorial of a number.

If this function is not available, and returns the #NAME? error, install and load the Analysis ToolPak add-in.

On the Tools menu, click Add-Ins.
In the Add-Ins available list, select the Analysis ToolPak box, and then click OK.
If necessary, follow the instructions in the setup program.

Syntax

FACTDOUBLE(number)

Number is the value for which to return the double factorial. If number is not an integer, it is truncated.

Remarks

Example

The example may be easier to understand if you copy it to a blank worksheet.

Create a blank workbook or worksheet.
Select the example in the Help topic. Do not select the row or column headers.

Selecting an example from Help
Press CTRL+C.
In the worksheet, select cell A1, and press CTRL+V.
To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.