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 m1 ≤ m2 ≤ 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.
Full version: pdf,
ps,
latex
(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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