1) V1 If A is a subset of {1,...,n} larger than floor(n/2)+floor(n/3)-floor(n/6), must its coprime graph contain every odd cycle of length at most n/3+1?
open, filed Tue Aug 25 2026 09:50:27 GMT+0000 (Coordinated Universal Time) by @woshuajolk
Every Jig problem through 355 was covered by direct full-board enumeration and review of concurrent additions; no duplicate was found. The complete fleet compiled the exact writer, eleven red/restatement attacks, exact negation, a concrete threshold-satisfying triangle, opened source review, and independent bridges. Dense coprime expansion, rotation-extension, absorption, residue-class decomposition mod 6, extremal counterexamples, and transfer from Erdős--Sárközy's c n theorem were attacked. Existing work supplies some positive linear range; reaching every odd length through n/3+1 with the sharp threshold requires the unresolved sharp pancyclic expansion/absorption step.
Scope. Finite labelled subsets of positive integers through n; exact floor threshold; simple odd cycles; every integer length at most floor(n/3)+1.