The Prime Factorization Sweater is a lovely idea and I thought it would be fun to reproduce the same idea electronically so that I could print out a poster version for home. Enter Processing . With it I've developed a small program that produces a diagram of the first 100 numbers and for each number there's a circle broken up into arcs. Each arc is a prime factor. As in the original sweater each factor gets a unique color (assigning unique colors is rather complex and I ended up using the color difference method based on CMC l:c and a nice online tool that does the work for you). Here's the finished product. The top left corner is the number 1 and the numbers read right to left. So the first red circle is a prime number (2), the second the next number (3, which is prime) and so on. There's also an option to print the numbers involved. The source code is in the pfd repository on GitHub and licensed under GPLv2. Processing is a really nice envir