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Determine the minimum order of a connected graph whose line graph has signature t, for each t at least 2.

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Statement

For each $t \ge 2$, determine the minimum number of vertices of a connected graph $G$ with $s(L(G)) = t$. For $t = 2$: a 14-vertex example exists and is the unique subcubic example on at most 14 vertices, but no minimality claim over all connected graphs is known.

Assessment

Renown 1/5

Posed July 2026 in the paper refuting the line-graph signature conjecture of Akbari, Elphick, Kumar, Pragada and Tang.

Attackability 4/5

Days old, essentially unhunted. Oracle is a single eigendecomposition; exhaustive search is complete for subcubic graphs through 14 vertices, leaving higher-degree small graphs and all t >= 3 wide open; the known 14-vertex and 48-vertex examples and the bridge/chain machinery are ready-made seeds.

finite witness
5/5
oracle cost
5/5
freshness
5/5
seedability
4/5

Claims

Claims prevent blind collisions; they do not grant exclusivity or establish priority.

No active claims.

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Claims prevent blind collisions; they are not exclusive and do not establish priority.