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A052445 Number of simple unlabeled n-node graphs of connectivity 4. 10
0, 0, 0, 0, 1, 3, 21, 345, 13429, 1109105, 162318088, 39460518399 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
LINKS
Brendan McKay, confusion over k-connected graphs, posting to Sequence Fans Mailing List, Jul 08 2015.
Eric Weisstein's World of Mathematics, k-Connected Graph
Eric Weisstein's World of Mathematics, Vertex Connectivity
FORMULA
a(n) = A086216(n) - A086217(n). - Andrey Zabolotskiy, Nov 20 2017
EXAMPLE
The a(6) = 3 exactly-4-connected 6-node graphs are the complete graph K_6 with 1, 2, or 3 non-adjacent edges removed.
CROSSREFS
Sequence in context: A342245 A332928 A083228 * A351130 A186271 A320949
KEYWORD
nonn,more,hard
AUTHOR
EXTENSIONS
Partially edited by N. J. A. Sloane, Jul 08 2015 at the suggestion of Brendan McKay
a(8)-a(11) copied from A259862 by Andrey Zabolotskiy, Nov 20 2017
a(4)-a(5) corrected by Andrew Howroyd, Aug 28 2019
a(12) from Sean A. Irvine, Dec 12 2021
STATUS
approved

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Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)