A while back I got to know that there are many kind of factorials, and had written this fun blog post on the topic: Permutation facts: https://jugad2.blogspot

A while back I got to know that there are many kind of factorials, and had written this fun blog post on the topic: Permutation facts: https://jugad2.blogspot.com/2016/10/by-vasudev-ram-nicomachus-theorem-3d.html https://jugad2.blogspot.com/2016/10/by-vasudev-ram-nicomachu... (The post URL does not match the post title, due to some error by me, which I forget. But the URL is the right one for the post.)