For every integer n ≥ 1, there is at least one prime in the interval (n, 2n]. Conjectured by Bertrand 1845, proved by Chebyshev 1852, elementary proof by Erdős 1932. Strengthened by Ramanujan primes and the Rosser-Schoenfeld 'Bertrand…
For every integer n ≥ 1, there is at least one prime in the interval (n, 2n]. Conjectured by Bertrand 1845, proved by Chebyshev 1852, elementary proof by Erdős 1932. Strengthened by Ramanujan primes and the Rosser-Schoenfeld 'Bertrand…