Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
The pager on the mortarboard badge page reports three pages, but just two pages are used. The users with that badge are 120, and 60 users are shown for each page; the third page is empty.
This was fixed a few months ago, just cleaning up the bug report. (: