and 
.
Description Returns the double-factorial of a specified number.
Syntax FACTDOUBLE ( number )
| Argument | Description |
|---|---|
| number | Any non-negative integer. If you supply a real number, FACTDOUBLE truncates the number to an integer before calculation. |
Remarks Double-factorials differ from factorials in that the decrement value (the amount of decrease in the variable) is 2 instead of one, denoted by the double exclamation point:
and
.
Examples This function returns 2027025:
This function returns 3840:
See Also FACT, FACTDOUBLE, PRODUCT
