User blog:SuperJedi224/Nested Multifactorial Notation

This is similar to Aarex Tiaokhiao's Nested Factorial Notation.

$$n!_{a}=\prod (\{x|0<x\leq n\text{ and }x(mod\,a)=n(mod\,a) \})$$ (The uppercase pi refers to the product of the values satisfying those conditions. Note that this is a multifactorial, not a nested factorial yet. Can also be written as n followed by a exclamation points under the rules of Multifactorials; n!2 is the same as n!!)

$$n!_{a}^{b}=(n!_{a}^{b-1})!_{a}; n!_{a}^{0}=n$$ (And here we have the nested factorial part; n!2 is the same as (n!)!.)

$$n!_{a}^{b}[z]=\text{int}\left(n!_{a}^{b}\,\times\frac{n!_{a}^{b}}{\left | n-z \right |!_{a}^{b}} \right )$$ (Just one more quick rule.)