Number of ways 3 domicules can be placed on an n X n square.

Terms

a(0) =0a(1) =0a(2) =0a(3) =180a(4) =4890a(5) =36028a(6) =154434a(7) =488660a(8) =1271450a(9) =2883900a(10) =5907298a(11) =11182644a(12) =19877850a(13) =33562620a(14) =54291010a(15) =84691668a(16) =128065754a(17) =188492540a(18) =270942690a(19) =381399220a(20) =526986138a(21) =716104764a(22) =958577730a(23) =1265800660a(24) =1650901530a(25) =2128907708a(26) =2716920674a(27) =3434298420