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A324061 Number of connected graphs on n unlabeled nodes with radius 2. 1
0, 0, 0, 2, 10, 76, 682, 9864, 245518, 11366961 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..10.

Eric Weisstein's World of Mathematics, Graph Radius

Wikipedia, Distance (graph theory)

CROSSREFS

Column k=2 of A324239.

Sequence in context: A124426 A321394 A320956 * A307524 A066223 A088500

Adjacent sequences:  A324058 A324059 A324060 * A324062 A324063 A324064

KEYWORD

nonn,more

AUTHOR

Andrew Howroyd, Sep 03 2019

STATUS

approved

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Last modified September 20 17:16 EDT 2020. Contains 337265 sequences. (Running on oeis4.)