On arithmetic terms expressing the prime-counting function and the n-th prime
Abstract
We present the first fixed-length elementary closed-form expressions for the prime-counting function, , and the -th prime number, . These expressions are arithmetic terms, requiring only a finite and fixed number of elementary arithmetic operations from the set: addition, subtraction, multiplication, integer division, and exponentiation. Mazzanti proved that every Kalmar function can be represented as an arithmetic term. We develop an arithmetic term representing the prime omega function, , which counts the number of distinct prime divisors of a positive integer . From this term, we find immediately an arithmetic term for the prime-counting function, . Combining these results with a new arithmetic term for binomial coefficients and novel prime-related exponential Diophantine equations, we manage to develop an arithmetic term for the -th prime number, , thereby providing a constructive solution to the fundamental question: Is there an order to the primes?
Cite
@article{arxiv.2412.14594,
title = {On arithmetic terms expressing the prime-counting function and the n-th prime},
author = {Mihai Prunescu and Joseph M. Shunia},
journal= {arXiv preprint arXiv:2412.14594},
year = {2025}
}
Comments
Four appendixes with codes and formulas; Revision includes corrections of several typos, including a typo which impacted the monomial expansion for the final p(n) term