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:

$n!! = \begin {cases} 1 & : n \in \set {0, 1} \\ n \paren {n - 2}!! & : n > 1 \end {cases}$