Bracket factorial
From timescalewiki
Let $\mathbb{T}$ be a time scale. Define the bracket factorial by $$[n]_{\mathbb{T}}! = \left\{ \begin{array}{ll} 1&; n=0 \\ \displaystyle\prod_{j=1}^n [j]_{\mathbb{T}} &; n=1,2,\ldots \end{array} \right.,$$ where $[j]_{\mathbb{T}}$ denotes a bracket number.
Properties
Gamma function on certain time scales at bracket number equals bracket factorial
