Does a 5-edge-connected, 5-regular Class 2 graph exist? A search for a possibly-missing snark, worked from public sources with every claim checked and every gap flagged.

Does χ*ℓ(G) > χℓ(G) + 1 ever hold? An open question in list packing / choosability, anchored on Cambie, Cames van Batenburg, Davies & Kang’s Packing list-colorings and Cambie’s open-problem listing, Problem 2.1.

A collaborative workshop for clearing the backlog of conjectured-but-unproven recurrences sitting in the On-Line Encyclopedia of Integer Sequences (OEIS) — one entry at a time, each proof citable, each documented dead end a scientific artifact.

Create topics here that don’t fit into any other existing category.

Discussion about this site, its organization, how it works, and how we can improve it.