%I A038144
%S A038144 0,0,0,0,0,1,2,13,67,404,2323,13517,76570,429320,2373965,13004323,
%T A038144 70641985,381260615,2046521491,10936624026,58228136539
%N A038144 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.
%C A038144 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.
%D A038144 J. V. Knop et al., On the total number of polyhexes, Match, No. 16 (1984), 
               119-134.
%H A038144 Joseph Myers, <a href="http://student.cusu.cam.ac.uk/~jsm28/tiling/">
               More information</a>
%Y A038144 Cf. A018190, A038143, A038147, A000228, A018190.
%Y A038144 Sequence in context: A045764 A106999 A054566 this_sequence A097977 A136780 
               A128743
%Y A038144 Adjacent sequences: A038141 A038142 A038143 this_sequence A038145 A038146 
               A038147
%K A038144 nonn
%O A038144 1,7
%A A038144 N. J. A. Sloane (njas(AT)research.att.com).
%E A038144 More terms from Joseph Myers (jsm(AT)polyomino.org.uk), May 05 2002
%E A038144 Further terms from Joseph Myers (jsm(AT)polyomino.org.uk), Nov 06 2003
%E A038144 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 05 2007