2010 Mathematics Game Update


[Photo by pfala.]

Thanks to John Cook’s article about factorials in the recent Mathematics and Multimedia Carnival, we’re adding new rules to the 2010 Mathematics Game.

Let’s play with multifactorials!

New Rules

(n!)! = a factorial of a factorial
n!! = a double factorial = the product of all integers from 1 to n that have the same parity (odd or even) as n
n!!! = a triple factorial = the product of all integers from 1 to n that are equal to n mod 3
n !^k = product of all integers from 1 to n that are equal to n mod k, where both n and k must be constructed from the year digits

I did a search this morning and realized that John’s article barely scratched the surface of the topic. I think we need to draw a line somewhere. So we will allow multifactorials (with the above limitation regarding n and k) but not subfactorials, superfactorials, hyperfactorials, alternating factorials, primorials, etc.

This week is hyper-busy, so I won’t have time to explore these new numbers for several days. But I look forward to hearing what you all come up with….


Don’t miss any of “Let’s Play Math!”:  Subscribe in a reader, or get updates by Email.


Have more fun on Let’s Play Math! blog:

About these ads

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s