I Went for a Drive

The way I heard it, Stanislaw Ulam, a mathematician, was very bored during a particularly dry lecture, so he started doodling. He wrote down the number 1. Then, on a rectangular grid, he continued writing down numbers, going from 2 to 3, then 4 and so on. He put them down in a counterclockwise spiral. On a hunch, he started circling prime numbers. He noticed a pattern, and so he kept writing, circling more primes. He quickly came to a realization: primes in this formation congregate along clearly defined diagonals. There is no reason why that should be. Primes were thought for centuries to be randomly distributed. In a moment of boredom and frustration, Ulam found the unexpected — a pattern, hidden in plain sight.

I’m laying out my own spiral.
I’m looking for a pattern.
I just don’t know what to circle.