A181528 Number of connected graphs with n edges embeddable into square lattice.

1, 1, 1, 2, 4, 6, 14, 28, 68, 156, 399, 1012, 2732, 7385, 20665, 58377, 168119, 488771

Offset

0,4

Comments

a(n) <= number of connected planar graphs with n edges A046091.

Links

Table of n, a(n) for n=0..17.

Andreas R. Hehn, Series Expansion Methods for Quantum Lattice Models, Doctoral Thesis, ETH Zürich, 2016.

Example

For n = 3 there are a(3) = 2 graphs: the claw graph, corresponding to a single free polystick, and the 3-path, corresponding to 4 different free polysticks.

Crossrefs

Cf. A046091, A019988 (embeddings, or free polysticks), A255539 (with n nodes, neighbors connected).

Sequence in context: A325868 A251581 A151794 * A251393 A058059 A053686

Adjacent sequences: A181525 A181526 A181527 * A181529 A181530 A181531

Keyword

nonn,more

Author

I. E. Kashuba (kashuba(AT)bitp.kiev.ua), Oct 27 2010

Extensions

Terms a(16)-a(17) from Hehn Table 3.1 and a(0) = 1 added by Andrey Zabolotskiy, Oct 22 2022

Status

approved