This article has not yet been rated on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Mathematics This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics articles ??? This article has not yet received a rating on the project's priority scale.

Virginia-American ( talk) 04:31, 9 January 2021 (UTC) reply

What sort of regularization? Is it Ramanujan summation, Cesàro summation, Borel summation, something else?

The Michael Penn video at https://www.youtube.com/watch?v=W-FBMPS-fJg gives a proof. In short, you define a function which gives the series at x=1, derive a first order linear differential equation which you then solve and evaluate at 1. Chalisque ( talk) 13:07, 19 December 2023 (UTC) reply