A 17-Year-Old's Cellular Automata Puzzle That Landed Him a Programming Job

Small-Grid Wraparound Cellular Automata

In a small wraparound grid of cellular automata, where each cell's next state depends only on how many of its eight neighbors are alive, how long can you go before a pattern repeats? The author proves the 3x3 case tops out at 4 unique states, then brute-forces 4x4 down from 65,536 starting configurations to 805 by filtering out translations, reflections, rotations, and inversions. The answer, computed in 2009, is 14 — and it helped him land his first programming job.