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Erdős Problem #489

If $A$ is a forbidden-divisor set with $|A \cap [1,x]| = o(\sqrt{x})$ and $B = \{b_1 < b_2 < \cdots\}$ the sifted set, must $x^{-1} \sum_{b_i < x} (b_{i+1} - b_i)^2$ converge to a finite limit?

Exact FrontierDelta

Prior state unknownproved

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Occurred: Jul 13, 2026

Delta type: SOURCE CLAIM

Assumptions: VibeMathed verification: lean-verified. Publication: announcement. AI contribution: ai-discovered. Imported under CC BY 4.0.

Canonical aliases: Erdős Problem #489 · Erdős #489 · Problem 489

Confidence: Not scored

Registry verification: lean verified · announcement · candidate

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VibeMathed
registry · event recorded by

GPT-5.6 starships (Claude Fable 5 reviewer)
model · ai model contributor · OpenAI / Anthropic

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This event attributed to GPT-5.6 starships (Claude Fable 5 reviewer)

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Erdős Problem #489 — Mathematical Frontier Network