The Strong Law of Small Numbers (1988) [pdf]

Example 5 has long been a favorite of mine. So easy to investigate, so geometrical, and there is a pattern, just not the obvious one.

That goes from sort of understandable to completely cryptic in about 3 pages

TLDR: You can't tell by looking (if your rule holds for all or only a small set of numbers).

You will need a maths degree for actually telling.

"Capricious coincidences cause careless conjectures."

> It will be proved by intimidation

Sounds like it worked!

Heh. You mean sort of understandable for part of the first sentence, ending with '35 examples of patterns." After that, no.