An effective analytic recurrence for prime numbers
Benoit Cloitre
TL;DR
The paper converts the non-constructive Golomb–Keller prime recurrence, originally involving a limit as $s\to\infty$, into a constructive method by proving that a finite parameter $s_n\le p_n$ suffices when paired with a ceiling. It derives tight bounds on $s_n$ (notably $s_n\le 2p_n$ and $s_n\le p_n$ via Bertrand and Nagura), establishes $\liminf_{n} s_n/p_n=0$ and $0.3823\lesssim \limsup s_n/p_n\le 0.4332$, and identifies a threshold constant $c_0\approx0.5956$ governing fixed-coefficient regimes. The work further connects $s_n$ to prime constellations, provides empirical distributional evidence for $\sigma_n=s_n/p_n$ (Beta-like with mean around 0.29), and extends the constructive framework to Dirichlet $L$-functions, enabling residue predictions modulo small integers through sign information. Overall, the approach yields a practical, constructive recurrence for primes with deep links to prime gaps, constellations, and Hardy–Littlewood-type conjectures, and it opens avenues for arithmetic information extraction via generalized $L$-functions.
Abstract
The Golomb--Keller formula expresses the next prime $p_{n+1}$ as a recurrence relation in terms of the first $n$ primes $p_1, \ldots, p_n$ using the Riemann zeta function and an Euler product, but requires taking a limit as $s \to \infty$, rendering it non-constructive. We transform this asymptotic formula into an effective recurrence by proving that a finite parameter $s \leq p_n$ suffices when combined with the ceiling function, establishing a constructive method valid for all $n \geq 1$. The minimal integer parameter $s_n$ (OEIS A389650) reveals deep connections to prime constellations. We prove $\liminf_{n\to\infty} σ_n = 0$ unconditionally, where $σ_n = s_n/p_n$. The limit superior $C = \limsup σ_n$ satisfies $\log ψ\lesssim C \leq 0.4332$, where $ψ\approx 1.46557$ is the supergolden ratio. The lower bound is conditional on the twin prime conjecture; the upper bound is unconditional. The constant $C$ relates to the densest admissible prime constellation, connecting to the Hardy--Littlewood conjectures. The method extends to Dirichlet L-functions, yielding other effective formulas for calculating $p_{n+1}$ but also for predicting residues of $p_{n+1}$ modulo any integer with reduced precision requirements.
