That's neat!

A number of years ago I attempted to create a program that would exhaustively evaluate short, digitless "dc" programs to find the shortest programs for all numbers under a million: https://emergent.unpythonic.net/01518231512 & a database of all my results for numbers up to 1 million: https://emergent.unpythonic.net/01525128151

While dc does have looping and function calls, my program didn't investigate their use; only straight-line dc programs are checked.

(dc is an rpn calculator available on many unix systems)