Number of n-step polygons on Kagome lattice.

Terms

a(0) =4a(1) =0a(2) =0a(3) =4a(4) =28a(5) =80a(6) =120a(7) =120a(8) =264a(9) =1080a(10) =3120a(11) =6440a(12) =11960a(13) =26688a(14) =70448a(15) =179340a(16) =415796a(17) =935560a(18) =2195536a(19) =5374468a(20) =13145420a(21) =31504224a(22) =74955600a(23) =180228984a(24) =438624648a(25) =1069909344a(26) =2600077824a(27) =6310088640a(28) =15363918432