A038140 Number of planar polyhexes with n cells and a single hole of size at least 2.

0, 0, 0, 0, 0, 0, 0, 1, 5, 43, 283, 1954, 12363, 76283, 453946, 2641506

Offset

1,9

Links

Table of n, a(n) for n=1..16.

Sven J. Cyvin, Jon Brunvoll, Björg N. Cyvin, John L. Bergan, and E. Brendsdal, The simplest coronoids: hollow hexagons, Struct. Chem., 2 (1991), 555-566.

J. V. Knop, W. R. Mueller, K. Szymanski, and N. Trinajstic, Use of small computers for large computations: enumeration of polyhex hydrocarbons, J. Chem. Inf. Comput. Sci., 30 (1990), 159-160.

Crossrefs

Cf. A018190, A038141, A323930, A038144.

Sequence in context: A221874 A317282 A182191 * A178826 A082311 A269121

Adjacent sequences: A038137 A038138 A038139 * A038141 A038142 A038143

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

Name clarified by Andrey Zabolotskiy, Feb 17 2023

Status

approved