%I M3186 #16 Aug 15 2020 19:55:27
%S 4,0,0,4,28,80,120,120,264,1080,3120,6440,11960,26688,70448,179340,
%T 415796,935560,2195536,5374468,13145420,31504224,74955600,180228984,
%U 438624648,1069909344,2600077824,6310088640,15363918432
%N Number of n-step polygons on Kagome lattice.
%D M. E. Fisher and M. F. Sykes, Excluded-volume problem and the Ising model of ferromagnetism, Phys. Rev. 114 (1959), 45-58.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%Y Cf. A001665.
%K nonn
%O 3,1
%A _N. J. A. Sloane_.
%E a(14)-a(22) from _Sean A. Irvine_, Jun 12 2016
%E a(23)-a(31) from _Sean A. Irvine_, Aug 15 2020