%I #8 Mar 30 2012 17:28:41
%S 1,1,3,7,22,77,294,1054,3788,11326,24790,103641,164559,532510,1574252,
%T 2939898,4761009,21048218,24306306,95707819,205176450
%N Number of polyhexes with n cells that tile the plane.
%D M. Gardner, Tiling with Polyominoes, Polyiamonds and Polyhexes. Chap. 14 in Time Travel and Other Mathematical Bewilderments. New York: W. H. Freeman, pp. 175-187, 1988.
%H Joseph Myers, <a href="http://www.polyomino.org.uk/mathematics/polyform-tiling/">Polyhex tiling</a>
%Y Cf. A000228-A070767, A018190-A070768, cf. A054359.
%K hard,nonn
%O 1,3
%A _Joseph Myers_, May 05 2002
%E More terms from _Joseph Myers_, Nov 06 2003
%E a(20) and a(21) from _Joseph Myers_, Nov 17 2010