A324264 Number of connected graphs on n unlabeled nodes with diameter equal to radius.

1, 1, 1, 2, 5, 28, 223, 3151, 79673, 3853870

Offset

1,4

Comments

When the graph diameter is equal to the radius, every node has the same eccentricity and is in both the graph center and the graph periphery.

Links

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

Eric Weisstein's World of Mathematics, Graph Center

Eric Weisstein's World of Mathematics, Graph Periphery

Wikipedia, Distance (graph theory)

Crossrefs

Rightmost diagonal of A294525 and A324244.

Sequence in context: A009635 A216401 A342288 * A138293 A316972 A068069

Adjacent sequences: A324261 A324262 A324263 * A324265 A324266 A324267

Keyword

nonn,more

Author

Andrew Howroyd, Sep 02 2019

Status

approved