Erdős Problem a Daythe open tracker

Erdős Problem #773

OPENdatabase updated 2025-08-31

No proof or disproof is known, and it isn't known whether a finite computation could settle it.

What the community database records, not our verdict. erdosproblems.com no longer shows statuses (why).

What is the size of the largest Sidon subset \(A\subseteq\{1,2^2,\ldots,N^2\}\)? Is it \(N^{1-o(1)}\)?
Statement as formalized in Formal Conjectures (Google DeepMind, Apache-2.0) · their label: research open. The authoritative wording is on erdosproblems.com/773.
Prizenone
Topicsnumber theory, sidon sets, squares
Statement in LeanFormal Conjectures
Solution in Leanno
OEISA390813
Original pageerdosproblems.com/773
FULL WRITE-UP BY THIS SITE · AUG 12, 2026

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Problem #773 asks whether the largest Sidon subset of the first N positive squares has size N^(1-o(1)); that asymptotic problem remains open. Conditional on the full published exact OEIS A390813 prefix through N=68, frozen exhaustive searches prove the next three values: a(69)=32, a(70)=33, and a(71)=33. The new upper search at 71 covers seven disjoint cubes and 114,296,406 recursive states; the size-33 lower witness is a direct integer certificate. An independent definition-level audit reconstructs every collision support and checks the witness, cube cover, and counters. This extends a finite table, not the exponent in Erdős's question.

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