Mathematician:Hudalrichus Regius

Mathematician
Dutch mathematician who showed that not all numbers of the form $2^n - 1$ for odd $n$ are prime.

He showed in $1536$ that $2^9 - 1 = 511 = 7 \times 73$, and also that $2^{11} - 1 = 2047 = 23 \times 89$.

Nationality
Dutch

History

 * Flourished: 1530s