k-Cyclic Graph
المؤلف:
Alon, N.; Yuster, R.; and Zwick, U
المصدر:
"Finding and Counting Given Length Cycles." Algorithmica 17
الجزء والصفحة:
...
1-3-2022
1633
k-Cyclic Graph

Graphs corresponding to closed walks of length
are known as
-cyclic graphs, or
-graphs for short.
-graphs are connected by definition. The numbers of
-graphs for
, 4, ... are 1, 3, 3, 10, 12, 35, 58, 160, 341, 958, 2444, 7242, 21190, 67217, 217335, ... (OEIS A081809; FlowProblems), the first few of which are illustrated above.
It appears that every connected simple graph on more than one node is
for some value of
. For example, every connected graph on six or fewer nodes with the exception of the complete graph
is
for some
.
These graphs are important when counting graph cycles. This is because the number of (undirected) closed
-walks in a graph with adjacency matrix
is given by
, where
denotes the matrix trace, but in order to compute the number
of
-cycles, all closed
-walks that are not cycles must be subtracted.
REFERENCES
Alon, N.; Yuster, R.; and Zwick, U. "Finding and Counting Given Length Cycles." Algorithmica 17, 209-223, 1997.
FlowProblem. "
-Graphs." http://flowproblem.ru/cycles/explicit-formulae/ck-graphs.
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