Uploaded May 2026 | Updated September 2026, 2 weeks ago

---

Featuring Neil Sloane - more details below. Gear Train (episode sponsor) is at metmo.co.uk/collections/gear-train with discount code NUMBERPHILE10OFF -- More links & stuff in full description below ↓↓↓

More Neil Sloane videos at: youtube.com/playlist?list=PLt5AfwLFPxWJXQqPe_llzWmTHMPb9QvV2

Neil Sloane is the founder of the OEIS: oeis.org

Lollipop Numbers: oeis.org/A389624

Patreon: patreon.com/numberphile

Numberphile is supported by Jane Street. Learn more about them (and exciting career opportunities) at: bit.ly/numberphile-janestreet

We are also grateful for support from the Ben Delo Foundation - delo.org

NUMBERPHILE
Website: numberphile.com

Video by Brady Haran and Pete McPartlan
Thanks also to Jonas Karlsson
Extra checking by the Numberphile Society - special mention to Debbie and Felipe

Numberphile T-Shirts and Merch: teespring.com/stores/numberphile

Brady's videos subreddit: reddit.com/r/BradyHaran

Brady's latest videos across all channels: bradyharanblog.com

Sign up for (occasional) emails: eepurl.com/YdjL9