Ask HN: Trying to find a specific math book

It would help if you specified whether the book is a textbook, if it's a dead tree book or ebook, or if it might even be an online "book" like the Stacks Project: https://stacks.math.columbia.edu/

Perhaps it's "An Infinitely Large Napkin" by Evan Chen? https://web.evanchen.cc/napkin.html

Yes, it's this one! Thank you so much.

This might be the thread you're talking about: https://news.ycombinator.com/item?id=30822339

Very interesting but I think the original thread was at least a month ago.