The generalized Petersen graph , also denoted
(Biggs 1993, p. 119; Pemmaraju and Skiena 2003,
p. 215), for
and
is a connected cubic graph consisting of an inner star
polygon
(circulant graph
) and an outer regular
polygon
(cycle graph
) with corresponding vertices in the inner and outer polygons
connected with edges. These graphs were introduced by Coxeter (1950) and named by
Watkins (1969). They should not be confused with the seven Petersen
family graphs.
For
even, the
-generalized
Petersen graph is sometimes defined (Alspach 1983) even though, unlike usual generalized
Petersen graphs, such graphs are not cubic.
Since the generalized Petersen graph is cubic, , where
is the edge count and
is the vertex count. More
specifically,
has
nodes and
edges.
Generalized Petersen graphs are implemented in the Wolfram Language as PetersenGraph[k,
n] and their properties are available using GraphData["GeneralizedPetersen",
k,
n
].
Generalized Petersen graphs may be further generalized to I graphs.
For
odd,
is isomorphic to
. So, for example,
,
,
,
, and so on. The numbers of nonisomorphic generalized
Petersen graphs on
, 8, ... nodes are 1, 1, 2, 2, 2, 3, 3, 4, 3, 5, 4, 5, 6,
6, 5, 7, ... (OEIS A077105).
is vertex-transitive iff
or
,
and symmetric only for the cases
, (5, 2), (8, 3), (10, 2), (10, 3), (12, 5), and
(24, 5) (Frucht et al. 1971; Biggs 1993, p. 119).
Tutte proved that has a unique 3-edge-coloring.
is the Nauru graph
and has LCF notation
(Frucht 1976).
All generalized Petersen graphs are unit-distance graphs (itnik et al. 2010). However, the only generalized Petersen
indices (some of which correspond to the same graph) which are unit-distance by twisting
correspond to , (6, 2), (7, 2), (7, 3), (8, 2), (8, 3), (9, 2),
(9, 3), (9, 4), (10, 2), (10, 3), (11, 2), (12, 2) (itnik et al. 2010).
The generalized Petersen graph is nonhamiltonian iff
and
(Alspach 1983; Holton and Sheehan 1993, p. 316).
Furthermore, the number of Hamiltonian cycles in
for
is given by
|
(1)
|
(Schwenk 1989; Holton and Sheehan 1993, p. 316).
The following table gives some special cases of the generalized Petersen graph.