Bertrand's postulate

Bertrand's postulate, a mathematical theorem, states that for any positive integer \( n \), there is always at least one prime number between \( n \) and \( 2n \). In simpler terms, if you take any whole number, say 5, there will be at least one prime number between 5 and 10 (in this case, 7). This idea was proposed by the French mathematician Joseph Bertrand in 1845 and was later proven true, highlighting that prime numbers are more common than one might initially think within intervals of natural numbers.