[#P3038] Erdős Problem 124: Sums of Distinct Powers with Nonzero Exponent Shift
Problem. Erdős Problem 124: Let $k$ be a nonzero integer, and let $D$ be a finite set of integers, each at least $3$, such that \[\sum_{d \in D} \frac{1}{d-1} \geq 1\] and $\gcd(D) = 1$. For each $d \in D$ and each integer $k \geq 0$, let $S(d,k)$ denote the set of natural numbers that can be written as \[\sum_{i \in s} d^i\] for some finite set $s$ of integers with $i \geq k$ for all $i \in s$. Does every sufficiently large natural number belong to the set \[\sum_{d \in D} S(d,k),\] that is, can it be expressed as $\sum_{d \in D} x_d$ where $x_d \in S(d,k)$ for each $d \in D$?
1Context
This problem is a variant of a classical question about representing integers as sums of numbers with restricted digits in multiple bases. The case $k = 0$ was solved affirmatively by Boris Alexeev. The case with $k \neq 0$ and the additional coprimality condition was conjectured by Burr, Erdős, Graham, and Li.
2Problem setup
Definition 1 (For integers $d \geq 2$ and $k \geq 0$, the set $S(d,k)$ of sums of distinct powers (with exponent at least $k$) consists of all natural numbers of the form $\sum_{i \in s} d^i$ where $s$). For integers $d \geq 2$ and $k \geq 0$, the set $S(d,k)$ of sums of distinct powers (with exponent at least $k$) consists of all natural numbers of the form $\sum_{i \in s} d^i$ where $s$ is a finite set of integers satisfying $i \geq k$ for all $i \in s$. Equivalently, these are numbers whose base-$d$ representation contains only digits $0$ or $1$, with all nonzero digits occurring at positions corresponding to exponents at least $k$.
Definition 2 (For a finite set $D$ of natural numbers, $\gcd(D)$). For a finite set $D$ of natural numbers, $\gcd(D)$ denotes the greatest common divisor of all elements of $D$.
Definition 3 (The notation $\sum_{d \in D} S(d,k)$). The notation $\sum_{d \in D} S(d,k)$ denotes the Minkowski sum of the sets $S(d,k)$ over all $d \in D$, consisting of all sums $\sum_{d \in D} x_d$ where $x_d \in S(d,k)$ for each $d \in D$.
Definition 4 (The phrase 'every sufficiently large natural number'). The phrase 'every sufficiently large natural number' means that there exists some natural number $N$ such that the property holds for all natural numbers $n \geq N$.
Remark 1. This problem is a variant of a classical question about representing integers as sums of numbers with restricted digits in multiple bases. The case $k = 0$ was solved affirmatively by Boris Alexeev. The case with $k \neq 0$ and the additional coprimality condition was conjectured by Burr, Erdős, Graham, and Li.
3What counts as a solution
- Give a rigorous proof or counterexample that completely resolves this statement: Erdős Problem 124: Let $k$ be a nonzero integer, and let $D$ be a finite set of integers, each at least $3$, such that \[\sum_{d \in D} \frac{1}{d-1} \geq 1\] and $\gcd(D) = 1$. For each $d \in D$ and each integer $k \geq 0$, let $S(d,k)$ denote the set of natural numbers that can be written as \[\sum_{i \in s} d^i\] for some finite set $s$ of integers with $i \geq k$ for all $i \in s$. Does every sufficiently large natural number belong to the set \[\sum_{d \in D} S(d,k),\] that is, can it be expressed as $\sum_{d \in D} x_d$ where $x_d \in S(d,k)$ for each $d \in D$?
1Status
Current status (Current status and unresolved remainder). OPEN as of 2026-07-31. The maintained Erdős Problems database at commit 8138974387d9030542daabe67faaa33eff9356f8 lists Problem 124 as open. The unresolved remainder is the full displayed statement. Give a rigorous proof or counterexample that completely resolves this statement: Erdős Problem 124: Let $k$ be a nonzero integer, and let $D$ be a finite set of integers, each at least $3$, such that \[\sum_{d \in D} \frac{1}{d-1} \geq 1\] and $\gcd(D) = 1$. For each $d \in D$ and each integer $k \geq 0$, let $S(d,k)$ denote the set of natural numbers that can be written as \[\sum_{i \in s} d^i\] for some finite set $s$ of integers with $i \geq k$ for all $i \in s$. Does every sufficiently large natural number belong to the set \[\sum_{d \in D} S(d,k),\] that is, can it be expressed as $\sum_{d \in D} x_d$ where $x_d \in S(d,k)$ for each $d \in D$?[1]
1Packet records
Recent contributions
These records are attached to this problem after the current published packet. Each badge shows its current verification or packet-review step.
Notes and companion material
Original intake status. OPEN as of 2026-07-31. The maintained Erdős Problems database at commit 8138974387d9030542daabe67faaa33eff9356f8 lists Problem 124 as open. The unresolved remainder is the full displayed statement.
- The maintained database entry for Erdős Problem 124 was open at commit 8138974387d9030542daabe67faaa33eff9356f8.
- The pinned Formal Conjectures declaration was matched by problem number and source locator.
- The controlled TheoremDB source corpus was checked for an already published record with the same slug.
How the 2 records connect
ProblemErdős Problem 124: Sums of Distinct Powers with Nonzero Exponent Shift
2See also
How to cite
TheoremDB contributors, “Erdős Problem 124: Sums of Distinct Powers with Nonzero Exponent Shift,” TheoremDB research memory, snapshot of July 31, 2026. https://theoremdb.org/statements/erdos-problem-124This page as plain text: erdos-problem-124.md
This problem includes 2 records joined by 1 typed links, sourced from erdosproblems.com[1], current as of July 31, 2026.
1References
- Packet source. Erdős Problems database, Problem 124, maintained status record. Erdős Problems record 124, checked 2026-08-01. Problem 124; status field and linked bibliography. ↗reference database · reference source · commit 8138974387d9030542daabe67faaa33eff9356f8 · checked 2026-07-31Source use: original summary.Records the current open status and links the literature attached to this exact numbered problem.Also cited at Problem 124; status snapshot 8138974387d9030542daabe67faaa33eff9356f8.Also cited at See dataset.references[0] for the exact external source and locator.Also cited at Editorial research route recorded 2026-07-31.Source used to formulate or check the problem record.Source used to assess the problem's recorded status.For Erdős Problem 124: Sums of Distinct Powers with Nonzero Exponent Shift: Records the current open status and links the literature attached to this exact numbered problem.Source named by the research packet.
- Erdős problem database, data/problems.yaml, commit 8138974387d9030542daabe67faaa33eff9356f8. Problem 124 entry in data/problems.yaml. ↗reference database · reference source · commit 8138974387d9030542daabe67faaa33eff9356f8 · checked 2026-07-31Source use: original summary.Pins the maintained database snapshot used for this release's dated status decision.Source used to assess the problem's recorded status.For Erdős Problem 124: Sums of Distinct Powers with Nonzero Exponent Shift: Pins the maintained database snapshot used for this release's dated status decision.
- Google DeepMind, Formal Conjectures, formal statement for Erdős Problem 124. GitHub commit bb1c69dab14ad895ac1ccdb7b0c0e0a67c8eb3e1. FormalConjectures/ErdosProblems/124.lean:L58; lemma erdos124.ne_zero; commit bb1c69dab14ad895ac1ccdb7b0c0e0a67c8eb3e1. ↗reference database · primary source · commit bb1c69dab14ad895ac1ccdb7b0c0e0a67c8eb3e1 · checked 2026-07-31Source use: original summary.Supplies the pinned formal declaration whose human-readable editorial statement is published here.Source used to assess the problem's recorded status.For Erdős Problem 124: Sums of Distinct Powers with Nonzero Exponent Shift: Supplies the pinned formal declaration whose human-readable editorial statement is published here.
Original TheoremDB editorial prose based on a pinned formal declaration and the maintained status database.