Lost anecdote of a mathematician who gave a presentation without saying a word

Question

Some weeks ago I saw in a blog post an anecdote of a mathematician who once gave a 'talk' (not really). The special thing was that he came directly to the chalkboard and started doing one computation that took several empty boards. Without saying a word during all the process (in fact all the presentation), when he put the last dot in the computation, the crowd started clapping excitedly.

I sort of remember and I wanted to come back to it to read it with more time, but I lost it. Now I have the doubt. Does anyone know about this anecdote? Who can this mysterious mathematician be?

Thanks!

Answer 1

Probably it was about Frank Nelson Cole's factorization of $2^{67}-1$. As Wikipedia says:

On October 31, 1903, Cole famously made a presentation to a meeting of the American Mathematical Society where he identified the factors of the Mersenne number $2^{67} − 1$, or $M_{67}$. Édouard Lucas had demonstrated in 1876 that $M_{67}$ must have factors (i.e., is not prime), but he was unable to determine what those factors were. During Cole's so-called "lecture", he approached the chalkboard and in complete silence proceeded to calculate the value of $M_{67}$, with the result being $147,573,952,589,676,412,927$. Cole then moved to the other side of the board and wrote $193,707,721 \times 761,838,257,287$, and worked through the tedious calculations by hand. Upon completing the multiplication and demonstrating that the result equaled $M_{67}$, Cole returned to his seat, not having uttered a word during the hour-long presentation. His audience greeted the presentation with a standing ovation. Cole later admitted that finding the factors had taken "three years of Sundays."

This MathOverflow question has a few more mathematical details, as well as a link to Cole's paper where he described his methods.