Counting Rocks!
This is the home page for an Open Educational Resources (OER) free online textbook and video series by Henry Adams, Rachel Pries, and myself. The textbook, called Counting Rocks!, was also coauthored by Kelly Emmrich and Shannon Golden.
Links to materials
Here is the latest version of the textbook, as of spring 2025:
Counting Rocks! An Introduction to Combinatorics
Here is the updated video series being created in spring 2025:
Here is the old video series made in Fall 2020:
Feedback Form
If you find any typos, please fill out the form below!
Your help in improving the textbook and videos is appreciated. If your typo correction or suggestion is incorporated, you will be listed in the preface of the next version of the textbook.