A uniquely graceful graph is a graph that has exactly one fundamentally distinct graceful labeling. Uniquely graceful graphs for , ..., 7, are illustrated above.
The numbers of uniquely graceful graphs of various types on , 2, ... vertices are summarized in the following table. Knuth (2024, Problem 97) enumerates uniquely graceful simple graphs in the connected and no isolated point cases up to 8 vertices.
OEIS | counts | type |
A379574 | 1, 1, 2, 5, 2, 5, 11, 33, ... | simple graphs |
A379572 | 0, 1, 2, 4, 1, 5, 10, 29, ... | simple graphs with no isolated points |
A379573 | 1, 1, 2, 4, 1, 4, 2, 19, ... | simple connected graphs |