Post #2735443

@Taneb@hacksrus.xyz Oh, did you make that? Nice! I didn't look at it while I was writing mine, but I did find it to compare once I was finished. The proofs are pretty similar in broad outlines, as one might expect, but yours is definitely more efficient: for example, to test whether a number has a factor I simply try every possible divisor less than it; my proof makes no attempt to stop when reaching the square root, as yours does.