An upper bound of 61 for the Ramsey number $R(3,3,3,3)$
We improve the upper bound on the classical Ramsey number $R(3,3,3,3)$ from 62 to 61. The proof is based on a global incidence count, classifications of small neighborhoods and exhaustive SAT computations. We formalize the mathematical reductions in Lean and refute every resulting formula with two SAT solvers.
Authors
- Milos Tatarevic
Publication Details
- Journal
- arXiv (Cornell University)
- Published
- 2026-10-27
- DOI
- https://doi.org/10.48550/arxiv.2610.36648
- Primary Topic
- Limits and Structures in Graph Theory
- Type
- preprint