Erdős Problem #390: the second-order constant for $f(n)-2n$

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This event attributed to Shouqiao Wang

This event attributed to ChatGPT 5.6

Erdős Problem #390: the second-order constant for $f(n)-2n$ parent of this event

The headline is the constant, and its two halves have different histories. The lower bound, $\liminf (f(n)-2n)/(n/\log n) \ge 4029639598/25970038185$, is not new here: it is Mausberg's thirteen-layer valuation cut, posted to the erdosproblems.com forum in May 2026 and credited as such in the paper. Its author wrote there that it "does not prove an upper bound, nor does it prove that an asymptotic constant exists." The novelty is the matching upper bound, so the claim is that the thirteen-layer bound is exactly tight. It is assembled from an exact cofactor-allocation certificate, central-binomial anchors, a guarded rough-signature selector, a friable-number covariance bridge, a finite-band tangent correction, and column-sparse rounding. That construction is what a reader should scrutinize; everything else is inherited or machine-checked. erdosproblems.com still lists #390 as open, and the paper calls itself a proposed solution. parent of this event

VibeMathed record: Erdős Problem #390: the second-order constant for $f(n)-2n$ evidence for this event

The green CI run whose log this review read (28 July 2026) evidence for this event

Forum thread: Tao on the obstruction, and Mausberg's thirteen-layer lower bound evidence for this event

Erdős Problem #390: the second-order constant for $f(n)-2n$ evidence for this event

Formal Conjectures: the upstream statement of Erdős 390, still marked open evidence for this event

erdosproblems.com #390 - still listed open evidence for this event

The Lean 4 development, with the Formal Conjectures bridge evidence for this event