https://peertube.lagbag.com/videos/watch/8a7d4e8e-3dd3-4ba7-840c-cf3545b5e1ea 💻 Code: https://thecodingtrain.com/challenges/167-prime-spiral ✨ Watch the uncut version on Nebula! https://nebula.tv/videos/codingtrain-the-prime-spiral-uncut-version-coding-challenge-167 ✨ Watch this video ad-free on Nebula! https://nebula.tv/videos/codingtrain-the-prime-spiral-coding-challenge-167 Why do prime numbers show up as diagonals in a spiral? In this video, I create a visualization in JavaScript (p5.js) of the Ulam Spiral (aka Prime Spiral) named for Polish Mathematician Stanislav Ulan. p5.js Web Editor Sketches: 🕹️ Prime (Ulam) Spiral: https://editor.p5js.org/codingtrain/sketches/0Ud-XsaYb 🕹️ Number Spiral: https://editor.p5js.org/codingtrain/sketches/Zs65bV-Al 🕹️ Prime vs Random Spiral: https://editor.p5js.org/codingtrain/sketches/3np1hBlXD 🕹️ Shapes & Color: https://editor.p5js.org/codingtrain/sketches/mCvvSKpZ5 🕹️ Incorporating 3D: https://editor.p5js.org/codingtrain/sketches/-eX078HZ5 🎥 Previous video: https://youtu.be/55iwMYv8tGI?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH 🎥 Next video: https://youtu.be/NJCiUVGiNyA?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH 🎥 All videos: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH References: 📺 CodingTrainChooChoo on Twitch: https://www.twitch.tv/codingtrainchoochoo 2️⃣ Mathematical Games: The remarkable lore of the prime numbers (1964): https://www.scientificamerican.com/article/mathematical-games-1964-03/ 📓 An Observation on the Distribution of Primes, M. Stein and S. M. Ulam: https://doi.org/10.2307/2314055 🗄 Prime Numbers (Wikipedia): https://en.wikipedia.org/wiki/Prime_number 🗄 List of Prime Numbers: https://en.wikipedia.org/wiki/List_of_prime_numbers 🔗 Download Processing 4: https://processing.org/download Videos: 🎥 Prime Spirals: https://youtube.com/watch?v=iFuR97YcSLM 🎶 Processing Theme Selector music by https://twitter.com/WillFromAmerica Timestamps: 0:00 Welcome! Choo choo! 0:23 History of the Ulam Spiral 1:16 Diagramming the Spiral 2:18 Starting to Code 3:25 How and when do I rotate? 4:25 Coding the number spiral 7:00 Debugging! 9:40 Visualizing the spiral 12:22 What is a prime number? 14:31 Code to check if a number is prime. 18:57 Marking primes in the spiral 19:40 Porting to Processing (Java) 22:46 More references & examples Editing by Mathieu Blanchette Animations by Jason Heglund Music from Epidemic Sound 🚂 Website: http://thecodingtrain.com/ 👾 Share Your Creation! https://thecodingtrain.com/guides/passenger-showcase-guide 🚩 Suggest Topics: https://github.com/CodingTrain/Suggestion-Box 💡 GitHub: https://github.com/CodingTrain 💬 Discord: https://thecodingtrain.com/discord 💖 Membership: http://youtube.com/thecodingtrain/join 🛒 Store: https://standard.tv/codingtrain 🖋️ Twitter: https://twitter.com/thecodingtrain 📸 Instagram: https://www.instagram.com/the.coding.train/ 🎥 Coding Challenges: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH 🎥 Intro to Programming: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6Zy51Q-x9tMWIv9cueOFTFA 🔗 p5.js: https://p5js.org 🔗 p5.js Web Editor: https://editor.p5js.org/ 🔗 Processing: https://processing.org 📄 Code of Conduct: https://github.com/CodingTrain/Code-of-Conduct This description was auto-generated. If you see a problem, please open an issue: https://github.com/CodingTrain/thecodingtrain.com/issues/new #primenumbers #p5js #javascript Tue, 07 Apr 2026 15:57:18 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://peertube.lagbag.com https://peertube.lagbag.com/client/assets/images/icons/icon-512x512.png https://peertube.lagbag.com/videos/watch/8a7d4e8e-3dd3-4ba7-840c-cf3545b5e1ea All rights reserved, unless otherwise specified in the terms specified at https://peertube.lagbag.com/about and potential licenses granted by each content's rightholder.