|
|
A052433
|
|
Number of perfect connected undirected simple graphs on n nodes.
|
|
5
|
|
|
1, 1, 2, 6, 20, 105, 724, 7805, 126777, 3122221, 112392709, 5736233644, 404604893810
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
COMMENTS
|
The triangle of the multiset transform (undirected simple graphs on n>=0 nodes with 0<=k<=n components) starts:
1
0 1
0 1 1
0 2 1 1
0 6 3 1 1
0 20 8 3 1 1
0 105 29 9 3 1 1
0 724 137 31 9 3 1 1
0 7805 890 146 32 9 3 1 1
0 126777 8859 926 148 32 9 3 1 1
0 3122221 136870 9043 935 149 32 9 3 1 1
0 112392709 3271052 138026 9079 937 149 32 9 3 1 1
0 5736233644 115835359 3281756 138215 9088 938 149 32 9 3 1 1
0 404604893810 5855863577 115988462 3282936 138251 9090 938 149 32 9 3 1 1 (R. J. Mathar, Mar 12 2018)
|
|
REFERENCES
|
A. Brandstaedt, V. B. Le and J. P. Spinrad, Graph Classes: A Survey, SIAM Publications, 1999.
|
|
LINKS
|
|
|
FORMULA
|
Inverse Euler transform of A052431.
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,hard,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|