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A108072 Number of self-dual planar polyhexes with n hexagons and having nontrivial symmetry. 2
1, 0, 0, 0, 0, 5, 22, 90, 342, 1247, 4491, 16095, 57906, 209170, 760830, 2784913, 10262649, 38051063, 141914613, 532131882, 2005320952, 7591794561, 28863820538, 110172051829, 422060152511, 1622369728951 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..26.

Gunnar Brinkmann, Gilles Caporossi and Pierre Hansen, A constructive enumeration of fusenes and benzenoids, Journal of Algorithms, Volume 45, Issue 2, November 2002, Pages 155-166.

Gunnar Brinkmann, Gilles Caporossi and Pierre Hansen, A Survey and New Results on Computer Enumeration of Polyhex and Fusene Hydrocarbons, J. Chem. Inf. Comput. Sci. 2003, 43, 3, 842-851.

CROSSREFS

Cf. A018190, A108070, A108071.

Sequence in context: A262293 A086090 A037529 * A081892 A128566 A097138

Adjacent sequences:  A108069 A108070 A108071 * A108073 A108074 A108075

KEYWORD

nonn

AUTHOR

Gunnar Brinkmann, Jun 05 2005

STATUS

approved

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Last modified March 2 09:45 EST 2021. Contains 341746 sequences. (Running on oeis4.)