The challenge wasn't print the largest prime under 4000, it was find the prime with the most digits. So the lisper example gave the wrong answer. Still need to generate the prime, count the digits and return the one with the most digits. No sure that the lisp version would be less lines of code, but I'll guess a recursive version would be close
It's not to find the one with the most digits. It's to find the widest one in Times New Roman. Times New Roman is not a fixed-width font, so the widest one might have less digits than some other one. For example I is less wide than M.
