Category:Double Factorials

This category contains results about Double Factorials.
Definitions specific to this category can be found in Definitions/Double Factorials.

The double factorial of $n$ is defined inductively as:

$n!! = \begin{cases}

1 & : n \in \left\{ {0, 1}\right\} \\ n \left({n - 2}\right)!! & : n > 1 \end{cases}$