CHEBYSHEV’S THEOREM AND BERTRAND’S POSTULATE
web.williams.edu › Mathematics › lg5CHEBYSHEV’S THEOREM AND BERTRAND’S POSTULATE LEO GOLDMAKHER ABSTRACT.In 1845, Joseph Bertrand conjectured that there’s always a prime between nand 2nfor any integer n>1. This was proved less than a decade later by Chebyshev; much more importantly, Chebyshev was led to prove the first good approximation to the prime number theorem.
Proof of Bertrand's postulate - Wikipedia
https://en.wikipedia.org/wiki/Proof_of_Bertrand's_postulateIn mathematics, Bertrand's postulate (actually a theorem) states that for each there is a prime such that . It was first proven by Chebyshev, and a short but advanced proof was given by Ramanujan. The following elementary proof was published by Paul Erdős in 1932, as one of his earliest mathematical publications. The basic idea is to show that the central binomial coefficients need to have a prime factor within the interval in order to be large enough. This is achieved through analys…