Let a graph be defined on vertex set and edge set . Then a construction sequence (or c-sequence) for is a linear order on in which each edge appears after both of its endpoints. The construction number of is then defined as the number of distinct construction sequences for (Kainen 2023).
For example, for the path graph with vertex set 1, 2, 3 and edge set 12, 23, there are 16 possible construction sequences (so ), one of which is (1, 2, 3, 23, 13) (Kainen 2023).
The construction numbers for a number of parametrized graph are summarized in the table below (cf. Kainen 2023), where is a Bernoulli number.
family | OEIS | construction number |
complete graph | A098694 | |
cycle graph | A024255 | |
empty graph | A000142 | |
ladder rung graph | A210277 | |
path graph | A000182 | |
star graph | A055546 |