Ulam Spiral
In 1963 Stanisław Ulam sketched the integers on a square spiral during a boring lecture and noticed primes cluster on diagonal lines. We borrow his layout for 1–69, color each cell by how often it's been drawn, and look for anything diagonal.
How it works
The spiral. Start at 1 in the center. Step right to 2, up to 3, left and down for 4–7, and so on — each lap outwards. All 69 numbers fit in a 9×9 region.
The color. Cell brightness is the total number of times that ball has been drawn across 1,339 draws since the October 2015 format change. If Powerball is uniform, every number should land near the expected count (total whites ÷ 69). Gold outlines mark primes; a blue outline marks the latest draw.
Primes form visible diagonals in the classic Ulam plot — that's a real pattern in the integers. Powerball frequencies, however, should look like textureless noise. If you spot a diagonal in the brightness, that's eyes-seeing-patterns-in-noise (apophenia), not a flaw in the lottery machine.