Journal of Integer Sequences, Vol. 27 (2024), Article 24.4.3

Empirical Verification of a Generalization of Goldbach's Conjecture


Zsófia Juhász
Dept. of Computer Algebra
Faculty of Informatics
Eötvös Loránd University
1117 Budapest
Hungary

Máté Bartalos

Péter Magyar and Gábor Farkas
Faculty of Informatics
Eötvös Loránd University Center Savaria
9700 Szombathely
Hungary

Abstract:

We test Hardy and Littlewood's generalization (GGC) of Goldbach's and Lemoine's conjectures. According to GGC, for relatively prime positive integers m1 and m2, every sufficiently large integer n satisfying certain simple congruence criteria can be expressed as n = m1 p + m2 q for some primes p and q. We check GGC up to 1012 for all (up to 1013 for some) relatively prime coefficients m1, m2 ≤ 40 and present the largest counterexamples that cannot be obtained in this form. We verify Lemoine's conjecture up to a new record of 1013. We compare the running times of four natural verification algorithms for all relatively prime m1m2 ≤ 40. The algorithms seek to find either the p- or the q-minimal (m1, m2)-partitions of all numbers tested, by either a descending or an ascending search for the prime to be maximized or minimized, respectively, in the partitions. For all m1, m2 descending searches were faster than ascending ones. We provide a heuristic explanation. The relative speed of ascending [descending] searches for the p- and the q-minimal partitions, respectively, varied by m1, m2. Using the average of p*m1, m2(n)—the minimal p in all (m1, m2)-partitions of n—up to a sufficiently large threshold, we introduce two functions of m1, m2, which may help predict these rankings. Our predictions correspond well with actual rankings, and could inform new verification efforts. Numerical data are presented, including average and maximum values of p*m1, m2(n) up to 109.


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(Concerned with sequences A000040 A002091 A002092 A046927 A194828 A195352 A195353 A195354.)


Received March 31 2023; revised versions received April 1 2023; July 24 2023; February 2 2024. Published in Journal of Integer Sequences, March 18 2024.


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