Why? Well, this is because a formula or expression that receives an integer at its input and always returns a prime number at its output, regardless of the numerical size, is humanly and technologically impossible. Prime numbers are infinite, and the larger they are, the more difficult it is to predict them without making mistakes, therefore the formula is not linear and its slope changes as the numbers grow. Due to this, since the entire number space generated by the primes cannot be known, Riemann's postulate cannot be verified either.