Featuring Sophie Maclean and superfactorials. Try the Halfsies challenge at https://brilliant.org/challenge/numberphile (and tell us your score!) or go to Brilliant's courses and start for free at https://brilliant.org/numberphile/ (episode sponsor) More links & stuff in full description below ↓↓↓ Sophie Maclean is based at Kings College, London: https://sophiethemathmo.wordpress.com/ More Sophie on Numberphile: https://bit.ly/Sophie_Numberphile Superpermutations: https://www.youtube.com/watch?v=wJGE4aEWc28 Superhero Triangles: https://www.youtube.com/watch?v=UIjeCKPHbso The Super Bottle: https://www.youtube.com/watch?v=8dHMpnfFdtc Patreon: http://www.patreon.com/numberphile Numberphile is supported by Jane Street. Learn more about them (and exciting career opportunities) at: https://bit.ly/numberphile-janestreet We're also supported by the Simons Laufer Mathematical Sciences Institute (formerly MSRI): http://bit.ly/MSRINumberphile Our thanks also to the Simons Foundation: https://www.simonsfoundation.org/ NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Video by Brady Haran and James Hennessy Numberphile T-Shirts and Merch: null Brady's videos subreddit: http://www.reddit.com/r/BradyHaran/ Brady's latest videos across all channels: http://www.bradyharanblog.com/ Sign up for (occasional) emails: http://eepurl.com/YdjL9