In 1847, Gabriel Lamé proved Fermat’s Last Theorem. Or so he thought. Lamé was a French mathematician who had made many important discoveries. In March of that year he sensed he’d made perhaps his biggest: an elegant proof of a problem that had rebuffed the most brilliant minds for more than 200 years.

His method had been hiding in plain sight. Fermat’s Last Theorem, which states that there are no positive integer solutions to equations of the form

a+^{n}b=^{n }cif^{n}nis greater than 2, had proved to be intractable. Lamé realized that he could prove the theorem if he just expanded his number system to include a few exotic values.