%I A006782 M1930
%S A006782 1,0,1,2,9,36,154,684,3128,14666,70258,342766
%N A006782 Number of polygons of length 4n on L-lattice.
%D A006782 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A006782 I. G. Enting and A. J. Guttmann, Self-avoiding polygons on the square, 
               L and Manhattan lattices, J. Phys. A 18 (1985), 1007-1017.
%Y A006782 Sequence in context: A052834 A150967 A121769 this_sequence A150968 A073156 
               A150969
%Y A006782 Adjacent sequences: A006779 A006780 A006781 this_sequence A006783 A006784 
               A006785
%K A006782 nonn
%O A006782 1,4
%A A006782 N. J. A. Sloane (njas(AT)research.att.com).