

A064513


Maximal number of nodes in graph of degree <= n and diameter 2 (another version).


1




OFFSET

1,1


COMMENTS

Comment from Allan C. Wechsler, Nov 22 2015: a(8) <= 65 by the Moore bound. Since 8 is not in {2,3,7,57}, we know a(8) <= 64. I don't know if we have any better upper bounds. This seems like a decent undergraduate research project. Pushing up the lower bound also.


LINKS

Guillermo PinedaVillavicencio; José Gómez; Mirka Miller, Hebert PérezRosés, New Largest Graphs of Diameter 6, Electronic Notes in Discrete Mathematics 24 (2006), 153160.


EXAMPLE

a(2) = 5 is achieved by the 5cycle.
a(3) = 10 is achieved by the Petersen graph.


CROSSREFS



KEYWORD

nonn,nice,hard,more


AUTHOR



EXTENSIONS

It is known that a(8) >= 57.


STATUS

approved



