|
| |
|
|
A005176
|
|
Number of regular graphs with n nodes.
(Formerly M0303)
|
|
13
| |
|
|
1, 2, 2, 4, 3, 8, 6, 22, 26, 176, 546, 19002, 389454, 50314870, 2942198546, 1698517037030
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
REFERENCES
| N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
P. Steinbach, Field Guide to Simple Graphs. Design Lab, Albuquerque NM, 1990.
|
|
|
LINKS
| E. Friedman, Illustration of small graphs
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
|
|
|
FORMULA
| a(n) = A005177(n) + A068932(n). - David Wasserman (dwasserm(AT)earthlink.net), Mar 08 2002
Row sums of triangle A051031.
|
|
|
CROSSREFS
| Not necessarily connected simple regular graphs: A005176 (any degree), A051031 (triangular array), specified degree k: A000012 (k=0), A059841 (k=1), A008483 (k=2), A005638 (k=3), A033301 (k=4), A165626 (k=5), A165627 (k=6), A165628 (k=7).
Simple regular graphs of any degree: A005177 (connected), A068932 (disconnected), A005176 (not necessarily connected).
Sequence in context: A056429 A133806 A185333 * A050335 A140860 A019681
Adjacent sequences: A005173 A005174 A005175 * A005177 A005178 A005179
|
|
|
KEYWORD
| nonn,nice,hard,more
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| More terms from David Wasserman (dwasserm(AT)earthlink.net), Mar 08 2002
Terms a(15) and a(16) were appended by Jason Kimberley (Jason.Kimberley(AT)newcastle.edu.au), Sep 25 2009
Crossrefs edited by Jason Kimberley (Jason.Kimberley(AT)newcastle.edu.au), Jan 06 2011
|
| |
|
|
