A296414 Number of non-isomorphic abstract almost-equidistant graphs on n vertices in R^2. A graph G is abstract almost-equidistant in R^2 if the complement of G does not contain K_3 and G does not contain K_4 nor K_{2,3}.

1, 2, 3, 6, 7, 9, 2, 1, 0

Offset

1,2

Comments

A set of points in R^d is called almost equidistant if for any three points, some two are at unit distance.

Links

Table of n, a(n) for n=1..9.

Martin Balko, Attila Pór, Manfred Scheucher, Konrad Swanepoel, and Pavel Valtr, Almost-equidistant sets, arXiv:1706.06375 [math.MG], 2017.

Martin Balko, Attila Pór, Manfred Scheucher, Konrad Swanepoel, and Pavel Valtr, Almost-equidistant sets [supplemental data], 2017.

Crossrefs

Cf. A296415, A296416, A296417, A296418, A296419, A006785.

Sequence in context: A066646 A215488 A110920 * A267590 A145266 A188078

Adjacent sequences: A296411 A296412 A296413 * A296415 A296416 A296417

Keyword

nonn,fini,full

Author

Manfred Scheucher, Dec 11 2017

Status

approved