Prunescu, M., & Sauras Altuzarra, L. (2024). An arithmetic term for the factorial function. Examples and Counterexamples, 5. https://doi.org/10.1016/j.exco.2024.100136
As proved by Marchenkov and Mazzanti, every Kalmar function can be represented by arithmetic terms. We display one of such terms to represent the factorial function, and as a consequence, we get an example of an arithmetic term which represents a function whose image is the set of primes.