The harmonic series and the elusive Euler–Mascheroni constant. More links & stuff in full description below ↓↓↓ Featuring Dr Tony Padilla. Audible: Extra footage: Videos about -1/12: Tony at the LHC: (via Sixty Symbols, our physics channel) Support us on Patreon: NUMBERPHILE Website: Numberphile on Facebook: Numberphile tweets: Subscribe: Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): Videos by Brady Haran Brady's videos subreddit: Brady's latest videos across all channels: Sign up for (occasional) emails: Numberphile T-Shirts: Other merchandise: