|
|
A359992
|
|
Number of connected spanning subgraphs in the n X n grid graph.
|
|
3
|
|
|
1, 5, 431, 555195, 10286937043, 2692324030864335, 9852929684161379901975, 501079193080617800221189943995, 352690403996687922642590703716802346343, 3426297680513758764075706102615040790667832304415, 458508006189588425325361635000918336126387961057365005349963
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
For n > 1, a(n) is the number of connected edge covers in the n X n grid graph.
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
The a(2) = 5 connected spanning subgraphs are the following subgraphs and their rotations and reflections.
o---o o---o
| | |
o---o o---o
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|