# Bertrand-Chebyshev theorem

## English[edit]

### Etymology[edit]

From the surname of Joseph Louis François Bertrand, who conjectured the theorem, and the surname of Pafnuty Chebyshev who proved it.

### Proper noun[edit]

- (mathematics) the theorem that there is at least one prime number between
*n*and 2*n*for every*n*>1, i.e.: