These are the show notes for episode 30 of the Travels in a Mathematical World Podcast. 30 is the largest number with the property that all smaller numberscoprime to it are prime. More about 30 from Number Gossip.

In the regular Maths History series, Noel-Ann Bradshaw of the University of Greenwich and also Meetings Co-ordinator of the British Society for the History of Mathematics talks about Ramanujan. You can read a biography of Ramanujan at the MacTutor History of Maths Archive.

You can find out more about my work with the IMA by following me on Twitter, reading this blog and visiting http://www.ima.org.uk/student/. Join the Facebook page.

N.B. **Correction** (26/05/09): In this episode Noel-Ann makes a slip of the tongue, saying “G.K. Hardy” which should be “G.H. Hardy”. We’re sorry!