Christopher Havens is serving a 25-year prison sentence for murder - but behind bars he's seeking redemption through advanced mathematics. He has published an academic paper... and is bringing math to other inmates via The Prison Mathematics Project. The Prison Mathematics Project - https://www.prisonmathproject.org/about/ The Paper: Linear fractional transformations and non-linear leaping convergents of some continued fractions - https://arxiv.org/abs/2002.12644 Article by Marta Cerruti on The Conversation - https://theconversation.com/an-inmates-love-for-math-leads-to-new-discoveries-130123 You can support Numberphile on Patreon - https://www.patreon.com/numberphile) like these people - https://www.numberphile.com/patrons With thanks to MSRI - https://www.msri.org