Double exponential growth is crazy fast, but some problem grow much faster and follow the hyperoperation sequence growth rate. Knuth wrote a fun paper in Scienc

Double exponential growth is crazy fast, but some problem grow much faster and follow the hyperoperation sequence growth rate. Knuth wrote a fun paper in Science in 1976 [1]. (Easy & interesting but sadly my link is to a paywall.) That was the first place I saw his arrow notation to describe some of these numbers. 5↑3 = 5*(5*5) 5↑↑3 = 5↑(5↑5) 5↑↑↑3 = 5↑↑(5↑↑5) 5↑↑↑↑3 = 5(↑^4)3 These numbers get BIG, the up arrow notation can express the Ackermann function. [1] https://science.sciencemag.org/content/194/4271/1235 https://science.sciencemag.org/content/194/4271/1235