{"document_url": "https://en.wikipedia.org/wiki/Negative_factorial"}
Negative factorial is factorial of negative numbers expressed, as

(-n)!= (-1)^n n! =(-1)(-2)(-3)......(-n+1)(-n)

It is calculated by using Codegym in Java (programming language)

It is represented by Euler's factorial function

,

-z)!=(-1)^z z! =