Will Cheatsheet #7 about Combinatorics be completed?

It would be very great for students if there was a cheatsheet on this topic.🦀🤔😼

I totally agree, feel free to submit a PR with Combinatorics cheatsheet :)

To begin with, you (or anyone passing by this GH issue) can sketch a list of topics you would like to see in a cheatsheet. Then, you can even provide some specific definitions and illustrations. Once we have a solid structure, anyone who wants to contribute can jump in and submit a draft PR. After that, we are going to polish it until it could be merged.