|
Search: id:A005642
|
|
|
| A005642 |
|
Number of 2-diregular connected digraphs with n nodes.
(Formerly M2689)
|
|
+0
1
|
|
| 1, 3, 7, 24, 117, 663, 4824, 40367, 381554, 4001849, 46043780, 576018785, 7783281188, 112953364381, 1752128923245, 28930230194371, 506596534953769
(list; graph; listen)
|
|
|
OFFSET
|
2,2
|
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
M. V. S. Ramanath; T. R. Walsh, Enumeration and generation of a class of regular digraphs, J. Graph Theory 11 (1987), no. 4, 471-479.
|
|
CROSSREFS
|
Sequence in context: A007172 A027610 A135688 this_sequence A019055 A041045 A041563
Adjacent sequences: A005639 A005640 A005641 this_sequence A005643 A005644 A005645
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
Search completed in 0.002 seconds
|
