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A108071 Number of self-dual planar polyhexes with n hexagons. 2
1, 1, 2, 4, 8, 21, 53, 151, 458, 1477, 4918, 16956, 59494, 212364, 766753, 2796876, 10284793, 38096072, 141998218, 532301941, 2005638293, 7592441954, 28865031086, 110174528925, 422064799013, 1622379252093 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

REFERENCES

Gunnar Brinkmann, Gilles Caporossi and Pierre Hansen, A constructive enumeration of fusenes and benzenoids, Journal of Algorithms 45 (2002), pp. 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., 43 (2003), 842-851.

LINKS

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

CROSSREFS

Cf. A018190, A108070, A108072.

Sequence in context: A216643 A002040 A162110 * A055876 A065847 A133604

Adjacent sequences:  A108068 A108069 A108070 * A108072 A108073 A108074

KEYWORD

nonn

AUTHOR

Gunnar Brinkmann (Gunnar.Brinkmann(AT)ugent.be), Jun 05 2005

STATUS

approved

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Last modified January 28 06:29 EST 2020. Contains 331317 sequences. (Running on oeis4.)