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Search: id:A038144
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| A038144 |
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Number of planar n-hexes, or polyhexes (in the sense of A000228, so rotations and reflections count as the same shape) with at least one hole. |
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+0
4
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| 0, 0, 0, 0, 0, 1, 2, 13, 67, 404, 2323, 13517, 76570, 429320, 2373965, 13004323, 70641985, 381260615, 2046521491, 10936624026, 58228136539
(list; graph; listen)
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OFFSET
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1,7
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COMMENT
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Apparently the same as the number of hexagonal planar circulenes (planar rings of hexagons) with n cells, although the two sequences may in fact differ for large n.
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REFERENCES
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J. V. Knop et al., On the total number of polyhexes, Match, No. 16 (1984), 119-134.
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LINKS
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Joseph Myers, More information
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CROSSREFS
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Cf. A018190, A038143, A038147, A000228, A018190.
Adjacent sequences: A038141 A038142 A038143 this_sequence A038145 A038146 A038147
Sequence in context: A045764 A106999 A054566 this_sequence A097977 A136780 A128743
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
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More terms from Joseph Myers (jsm(AT)polyomino.org.uk), May 05 2002
Further terms from Joseph Myers (jsm(AT)polyomino.org.uk), Nov 06 2003
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 05 2007
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