On Apr 23, 2022, at 3:25 PM, Henry Laxen wrote:

 Dear Group,

Many years ago I read a fascinating article which I can't seem to find anymore. It was about writing down (in english) the numbers from one to a billion? and being able to retrieve the nth letter. ie:

onetwothreefourfive...ninehundredninetymillion....ninetynineonebillion

I remember it used near semi rings and automatic differentiation, but no matter how I use those words to search (both google and duckduck) I can't find it. Do any of you have a pointer. I believe the code was written in haskell too.

Best wishes, Henry Laxen

One of my all-time favorites, too! http://conway.rutgers.edu/~ccshan/wiki/blog/posts/WordNumbers1/ Anthony