Furstenberg’s topological proof of the infinitude of primes

I just returned from a 10-day trip to India. It was my first visit there. I gave a talk at the ICM Satellite Conference: Various Aspects of Dynamical Systems. The conference was hosted by the Department of Mathematics at the M. S. University, Baroda, which is in Vadodara (formerly Baroda) in the Indian state of…

More prime phone numbers

Recently I noticed that Jenny’s phone number 8675309 (867-5309) had some interesting number theoretic properties. So, this evening I decided to punch my own phone number into Wolfram|Alpha to see what I’d find. Amazingly, both my 7-digit phone number and my full 10-digit phone number are prime numbers! That’s so excellent. (Unfortunately, putting a 1…

The prime number theorem in Calculus II

I attended Shahriar Shahriari’s MAA Minicourse Beyond Formulas and Algorithms: Teaching a Conceptual/thematics Single Variable Calculus Course at the 2008 Joint Mathematics Meeting. He talked about having his calculus students derive the prime number theorem. Recall that the prime number theorem states that if is the number of primes less than or equal to ,…