The Fibonacci sequence taken modulo m repeats, and the length of that repeat is the Pisano period. Plot the residues and the repetition becomes a figure — different for every modulus, symmetric in ways that are not obvious from the arithmetic.
Two renderers over one core draw Fibonacci, Lucas and related integer sequences under modular arithmetic, live and interactively. Built after Jacob Yatsko's video A New Way to Look at Fibonacci Numbers, including the questions it raises and leaves open. A gallery of pre-generated figures is at /gallery/.
A gallery of generated figures — every design drawn from the Pisano period of its modulus
Source code: github.com/0magnet/pisano. More Go and WebAssembly projects: magnetosphere.net/software.