The numbers of cubic hypohamiltonian graphs on 2, 4, 6, ... vertices are 0, 0, 0, 0, 1, 0, 0, 0, 2, 1, 3, 1, 100, 52, 202, 304, ... (OEIS A305354; Goedgebeur and Zamfirescu 2017).
The following figure and table and summarize small named cubic hypohamiltonian graphs.
vertex count | cubic hypohamiltonian graphs |
10 | Petersen graph |
18 | |
20 | 5-flower snark |
22 | generalized
Petersen graph |
24 | 24-Thomassen graph |
26 | |
28 | Coxeter graph, 7-flower snark |
30 | double star snark |