|
|
A339142
|
|
Number of (undirected) cycles in the graph C_5 X P_n.
|
|
5
|
|
|
1, 52, 733, 9394, 119235, 1512196, 19177677, 243212478, 3084441599, 39117172360, 496087629441, 6291429718962, 79788500460003, 1011885230273244, 12832823194696645, 162747064808635206, 2063973507784856167, 26175505197898511728, 331960206747350288969, 4209950410912939269210
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
PROG
|
(Python)
# Using graphillion
from graphillion import GraphSet
def make_CnXPk(n, k):
grids = []
for i in range(1, k + 1):
for j in range(1, n):
grids.append((i + (j - 1) * k, i + j * k))
grids.append((i + (n - 1) * k, i))
for i in range(1, k * n, k):
for j in range(1, k):
grids.append((i + j - 1, i + j))
return grids
universe = make_CnXPk(5, n)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles()
return cycles.len()
print([A339142(n) for n in range(1, 9)])
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
More terms from Ed Wynn, Jun 28 2023
|
|
STATUS
|
approved
|
|
|
|