(Narrated by Byungchul Cha) It all began in 2014 when Gabe Feinberg, who is a Muhlenberg alum (’04), a PhD (’13) from UConn and was a post doc at Swarthmore College at that time, gave an undergraduate colloquium talk at Muhlenberg College.
Gabe presented a wonderful theorem on generation of primitive Pythagorean triples (PPT), that is, positive integer triples \( (a, b, c) \) without common factor satisfying \( a^2 + b^2 = c^2 \). Here is the statement of the theorem.
Gabe’s presentation largely followed the proof given in an article by Keith Conrad. This theorem, which we later came to call Berggren’s Theorem, appears to have been repeatedly (re)discovered by many authors independently. As far as we are aware, Berggren’s 1934 article is the oldest literature containing this theorem.
I was fascinated by the simplicity of this theorem. I believe Berggren’s theorem deserves much wider recognition and I try to publicize it widely whenever I have an opportunity to do so. Later, Emily Nguyen (’15)
