Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

Terms

a(0) =9a(1) =81a(2) =324a(3) =900a(4) =2025a(5) =3969a(6) =7056a(7) =11664a(8) =18225a(9) =27225a(10) =39204a(11) =54756a(12) =74529a(13) =99225a(14) =129600a(15) =166464a(16) =210681a(17) =263169a(18) =324900a(19) =396900a(20) =480249a(21) =576081a(22) =685584a(23) =810000a(24) =950625a(25) =1108809a(26) =1285956a(27) =1483524a(28) =1703025a(29) =1946025