

A337179


Number of geodetic graphs with n unlabeled vertices.


1



1, 1, 2, 4, 10, 23, 66, 185, 586, 1880, 6360, 21975, 78230, 283087, 1043329, 3895505, 14726263, 56234210, 216719056, 841857211, 3293753840, 12969219563
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OFFSET

1,3


COMMENTS

A graph is geodetic if each pair of vertices is joined by a unique shortest path. To obtain this sequence, nonisomorphic graphs were generated using Brendan McKay's nauty program, then the geodetic property is checked on this output.


LINKS

Brendan McKay and Adolfo Piperno, nauty and Traces. [nauty and Traces are programs for computing automorphism groups of graphs and digraphs.]


EXAMPLE

For n=4 there are a(4)=4 geodetic graphs: a triangle with another edge attached to one vertex, an edge path of length 3, a tripod of 3 edges joined at a common vertex, and a complete graph on 4 vertices.
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ooo, oooo, ooo, \/
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PROG



CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS

a(12)a(22) from Florian Stober and Armin Weiß added by Murray Elder, Nov 14 2023


STATUS

approved



