Sum of consecutive powers as a perfect power
Pith reviewed 2026-05-20 00:02 UTC · model grok-4.3
The pith
The Diophantine equation x^k + (x+1)^k = y^n has only the trivial solutions x=0 and x=-1 when k ≡ 2 mod 4, n≥3, for k from 6 to 100 or when k's odd prime factors are all congruent to 3 mod 4.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We study the equation x^k + (x+1)^k = y^n with n ≥ 3 and k ≡ 2 (mod 4). We prove that the only solutions are for x = 0, -1 when 6 ≤ k ≤ 100 or for a k with odd prime factors congruent to 3 mod 4. The proof relies on linear forms in logarithms, the modular method, and the resolution of Thue equations.
What carries the argument
Linear forms in logarithms to obtain effective upper bounds on solutions, combined with the modular method to handle large exponents and Thue equations for small cases.
Load-bearing premise
The linear forms in logarithms and the modular method together produce effective bounds that cover all possible solutions without exception for the stated range of k.
What would settle it
A counterexample would be an integer x not equal to 0 or -1, k between 6 and 100 with k congruent to 2 modulo 4, n at least 3, and y such that x^k + (x+1)^k equals y^n.
read the original abstract
In this paper we study the equation $$ x^k + (x+1)^k = y^n,\quad n\geq 3, $$ when $k\equiv 2\pmod{4}$. We prove that the only solutions are for $x=0, -1$ when $6\leq k\leq 100$ or for a $k$ with odd prime factors congruent to $3\pmod{4}$. We use linear forms in logarithms, the modular method and the resolution of Thue equations.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript studies the Diophantine equation x^k + (x+1)^k = y^n with n ≥ 3 and k ≡ 2 (mod 4). It claims to prove that the only integer solutions are the trivial ones with x = 0 or x = -1, specifically when 6 ≤ k ≤ 100, or more generally whenever k possesses an odd prime factor congruent to 3 (mod 4). The proof strategy combines bounds from linear forms in logarithms, followed by the modular method (via Frey-Hellegner curves and level lowering) and resolution of associated Thue equations to eliminate non-trivial solutions.
Significance. If the central claim holds, the result would be a solid contribution to the study of superelliptic equations and sums of consecutive powers, extending known finiteness results to an explicit finite range of even exponents k ≡ 2 mod 4 up to 100. The combination of Baker-type bounds with modular arithmetic and Thue solvers is a standard effective toolkit in this area; successful application here, particularly if explicit computable bounds B(k) are derived and verified to be within reach of the subsequent methods, would merit credit for completing the case analysis without leaving unhandled ramification or height issues.
major comments (1)
- [Abstract and methods paragraph] Abstract, methods paragraph: The central claim for 6 ≤ k ≤ 100 rests on linear forms in logarithms producing an explicit, computable upper bound B(k) on |x| (depending on k and n) such that the modular method or Thue-equation resolution then eliminates all non-trivial solutions with |x| < B(k). The manuscript does not supply the explicit values of these B(k) or the precise constants arising from the linear-form estimates for k near 100; without them it is impossible to confirm that the height growth with k remains compatible with practical exhaustive checking and that no ramification cases (e.g., when n shares prime factors with k) are left unhandled.
minor comments (2)
- [Introduction] The statement of the main theorem would benefit from an explicit list of the small k values (6, 10, …, 98, 100) that were checked individually, together with a brief indication of which auxiliary tool (modular or Thue) was applied to each.
- [Abstract] Notation for the exponent n and the variable y should be introduced consistently before the first display of the equation to avoid any momentary ambiguity with the exponent k.
Simulated Author's Rebuttal
We thank the referee for their careful reading and constructive feedback on our manuscript. We address the major comment below and will revise the manuscript to provide the requested explicit details.
read point-by-point responses
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Referee: Abstract, methods paragraph: The central claim for 6 ≤ k ≤ 100 rests on linear forms in logarithms producing an explicit, computable upper bound B(k) on |x| (depending on k and n) such that the modular method or Thue-equation resolution then eliminates all non-trivial solutions with |x| < B(k). The manuscript does not supply the explicit values of these B(k) or the precise constants arising from the linear-form estimates for k near 100; without them it is impossible to confirm that the height growth with k remains compatible with practical exhaustive checking and that no ramification cases (e.g., when n shares prime factors with k) are left unhandled.
Authors: We agree that the manuscript would be strengthened by including the explicit upper bounds B(k) and the constants from the linear forms in logarithms. In the revised version we will add an appendix listing the computed B(k) for each k from 6 to 100, together with the precise constants arising from the chosen theorem on linear forms (e.g., Matveev’s theorem with explicit numerical values). This will make the growth of the bounds transparent and confirm that they remain within the range where the modular method and Thue-equation solvers can be applied in practice. Regarding ramification when n and k share prime factors, Section 3 of the manuscript already treats these cases by first determining gcd(n,k) and then applying level lowering to the Frey–Hellegner curve only after verifying that the conductor and the ramification at primes dividing the level are controlled; we will add a short clarifying paragraph to make this separation explicit and to confirm that no subcases are omitted. revision: yes
Circularity Check
No circularity: proof applies independent external theorems
full rationale
The paper proves a finiteness result for the Diophantine equation x^k + (x+1)^k = y^n (n≥3, k≡2 mod 4) by combining linear forms in logarithms (to produce explicit upper bounds on |x|), the modular method (Frey-Hellegner curves and level lowering), and effective resolution of associated Thue equations. These are drawn from prior, independently established literature (Baker-type theorems, modularity theorem, Ribet's level-lowering, and Thue solvers) whose correctness is external to the present work and does not rely on any quantity defined or fitted inside the paper. No step equates a derived quantity to an input by construction, renames a known pattern, or loads the central claim on a self-citation chain. The derivation is therefore self-contained against external benchmarks.
Axiom & Free-Parameter Ledger
axioms (2)
- standard math Effectiveness of linear forms in logarithms for bounding exponential Diophantine equations
- domain assumption Modular method applies to the Frey curve attached to the equation
Lean theorems connected to this paper
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IndisputableMonolith/Foundation/ArithmeticFromLogic.leanlogicNat_initial unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
We use linear forms in logarithms, the modular method and the resolution of Thue equations... attach the Frey-Hellegouarch curve E: Y² = X³ + 2x X² + 2 d2/d1 y1^n X
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IndisputableMonolith/Foundation/AlexanderDuality.leanalexander_duality_circle_linking unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
Theorem 1.1. Suppose k≡2 (mod 4). If 6≤k≤100, then the only solutions ... result when x∈{-1,0}
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
Works this paper leans on
-
[1]
Abu Muriefah, Florian Luca, Samir Siksek, and Szabolcs Tengely
Fadwa S. Abu Muriefah, Florian Luca, Samir Siksek, and Szabolcs Tengely. On the Diophantine equation x2 +C= 2y n.Int. J. Number Theory, 5(6):1117–1128, 2009
work page 2009
-
[2]
Michael A. Bennett, Jordan S. Ellenberg, and Nathan C. Ng. The Diophantine equationA4+2δB2 =C n. Int. J. Number Theory, 6(2):311–338, 2010
work page 2010
-
[3]
Bennett, Vandita Patel, and Samir Siksek
Michael A. Bennett, Vandita Patel, and Samir Siksek. Superelliptic equations arising from sums of consecutive powers.Acta Arith., 172(4):377–393, 2016
work page 2016
-
[4]
Bennett, Vandita Patel, and Samir Siksek
Michael A. Bennett, Vandita Patel, and Samir Siksek. Perfect powers that are sums of consecutive cubes.Mathematika, 63(1):230–249, 2017
work page 2017
-
[5]
Michael A. Bennett and Chris M. Skinner. Ternary Diophantine equations via Galois representations and modular forms.Can. J. Math., 56(1):23–54, 2004
work page 2004
-
[6]
On the modularity of elliptic curves overQ: wild 3-adic exercises.J
Christophe Breuil, Brian Conrad, Fred Diamond, and Richard Taylor. On the modularity of elliptic curves overQ: wild 3-adic exercises.J. Amer. Math. Soc., 14(4):843–939, 2001
work page 2001
-
[7]
Classical and modular approaches to exponential Diophantine equations
Yann Bugeaud, Maurice Mignotte, and Samir Siksek. Classical and modular approaches to exponential Diophantine equations. II. The Lebesgue-Nagell equation.Compos. Math., 142(1):31–62, 2006
work page 2006
-
[8]
J. W. S. Cassels. A Diophantine equation.Glasgow Math. J., 27:11–18, 1985
work page 1985
-
[9]
J. H. E. Cohn. Perfect Pell powers.Glasgow Math. J., 38(1):19–20, 1996. 16
work page 1996
-
[10]
Power values of power sums: a survey
Nirvana Coppola, Mar Curc´ o-Iranzo, Maleeha Khawaja, Vandita Patel, and ¨Ozge ¨Ulkem. Power values of power sums: a survey. InWomen in numbers Europe IV—research directions in number theory, volume 32 ofAssoc. Women Math. Ser., pages 155–193. Springer, Cham, [2024]©2024
work page 2024
-
[11]
Rigid local systems, Hilbert modular forms, and Fermat’s last theorem.Duke Math
Henri Darmon. Rigid local systems, Hilbert modular forms, and Fermat’s last theorem.Duke Math. J., 102(3):413–449, 2000
work page 2000
-
[12]
Winding quotients and some variants of Fermat’s last theorem.J
Henri Darmon and Lo¨ ıc Merel. Winding quotients and some variants of Fermat’s last theorem.J. Reine Angew. Math., 490:81–100, 1997
work page 1997
- [13]
-
[14]
Reclam-Verlag, Stuttgart, 1959
Leonhard Euler.Vollst¨ andige Anleitung zur Algebra. Reclam-Verlag, Stuttgart, 1959
work page 1959
-
[15]
A. Kraus and J. Oesterl´ e. Sur une question de B. Mazur.Math. Ann., 293(2):259–275, 1992
work page 1992
-
[16]
Sur l’´ equationa3 +b 3 =c p.Experiment
Alain Kraus. Sur l’´ equationa3 +b 3 =c p.Experiment. Math., 7(1):1–13, 1998
work page 1998
-
[17]
Linear forms in two logarithms and interpolation determinants
Michel Laurent. Linear forms in two logarithms and interpolation determinants. II.Acta Arith., 133(4):325–348, 2008
work page 2008
-
[18]
Perfect powers that are sums of consecutive squares.C
Vandita Patel. Perfect powers that are sums of consecutive squares.C. R. Math. Acad. Sci. Soc. R. Can., 40(2):33–38, 2018
work page 2018
-
[19]
On powers that are sums of consecutive like powers.Res
Vandita Patel and Samir Siksek. On powers that are sums of consecutive like powers.Res. Number Theory, 3:Paper No. 2, 7, 2017
work page 2017
-
[20]
K. A. Ribet. On modular representations of Gal( Q/Q) arising from modular forms.Invent. Math., 100(2):431–476, 1990
work page 1990
-
[21]
Sur les repr´ esentations modulaires de degr´ e 2 de Gal(Q/Q).Duke Math
Jean-Pierre Serre. Sur les repr´ esentations modulaires de degr´ e 2 de Gal(Q/Q).Duke Math. J., 54(1):179– 230, 1987
work page 1987
-
[22]
Smart.The algorithmic resolution of Diophantine equations, volume 41 ofLond
Nigel P. Smart.The algorithmic resolution of Diophantine equations, volume 41 ofLond. Math. Soc. Stud. Texts. Cambridge: Cambridge University Press, 1998
work page 1998
-
[23]
R. J. Stroeker. On the sum of consecutive cubes being a perfect square. volume 97, pages 295–307. 1995. Special issue in honour of Frans Oort
work page 1995
-
[24]
Ring-theoretic properties of certain Hecke algebras.Ann
Richard Taylor and Andrew Wiles. Ring-theoretic properties of certain Hecke algebras.Ann. of Math. (2), 141(3):553–572, 1995
work page 1995
-
[25]
Bordeaux.PARI/GP version2.17.1, 2024
The PARI Group, Univ. Bordeaux.PARI/GP version2.17.1, 2024. available fromhttp://pari.math. u-bordeaux.fr/
work page 2024
-
[26]
On a Diophantine equation.Proc
Saburˆ o Uchiyama. On a Diophantine equation.Proc. Japan Acad. Ser. A Math. Sci., 55(9):367–369, 1979
work page 1979
-
[27]
Modular elliptic curves and Fermat’s last theorem.Ann
Andrew Wiles. Modular elliptic curves and Fermat’s last theorem.Ann. of Math. (2), 141(3):443–551, 1995
work page 1995
-
[28]
On the Diophantine equation (x−1) k +x k + (x+ 1) k =y n.Publ
Zhongfeng Zhang. On the Diophantine equation (x−1) k +x k + (x+ 1) k =y n.Publ. Math. Debrecen, 85(1-2):93–100, 2014. Department of Mathematics, Aristotle University of Thessaloniki, School of Science, 3rd floor, office 17, 54124, Thessaloniki, Greece Email address:akoutsianas@math.auth.gr Department of Mathematics & Applied Mathematics, University of Cre...
work page 2014
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