%I #5 Jun 27 2018 18:43:39
%S 0,0,1,1,1,4,3,10,9,36,27,129,90,449,331
%N Number of symmetric self-avoiding polygons on hexagonal lattice with perimeter n, not counting rotations and reflections as distinct.
%H Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a284869.htm">Illustration of polygons of perimeter <= 11</a>.
%Y Cf. A036418, A284869, A306176.
%K nonn,walk,more
%O 1,6
%A _Hugo Pfoertner_, Jun 27 2018