The alternating harmonic series 1 – 1/2 + 1/3 – 1/4 + 1/5 – 1/6 + … can be rearranged to approach any limit you want! This amazing fact (a special case of the Riemann rearrangement theorem) is elegantly illustrated by this applet https://t.co/d06ntY8xBP (ht @paultpearson). pic.twitter.com/Ve3pNRCFPp

— Steven Strogatz (@stevenstrogatz) August 19, 2020

There's a terrific write-up of Riemann's Rearrangement Theorem here, https://t.co/np3UEVTtcs, from an old issue of @NCTM's Mathematics Teacher.

— Patrick Honner (@MrHonner) August 19, 2020