Orders of nut graphs with prescribed vertex and edge orbit counts
Determine, for every r ∈ N and k ≥ r + 1, all graph orders n for which there exists a nut graph of order n with exactly r vertex orbits and k edge orbits.
References
We conclude the paper with another natural problem. Problem 21. For any r E N and k ≥ r + 1, determine all the orders for which there exists a nut graph with r vertex orbits and k edge orbits.
— Nut graphs with a prescribed number of vertex and edge orbits
(2502.20201 - Bašić et al., 27 Feb 2025) in Problem 21, Section 5, Conclusion