Number of (n+2) X 4 binary arrays avoiding patterns 001 and 011 in rows and columns.

Terms

a(0) =324a(1) =1296a(2) =3600a(3) =10000a(4) =22500a(5) =50625a(6) =99225a(7) =194481a(8) =345744a(9) =614656a(10) =1016064a(11) =1679616a(12) =2624400a(13) =4100625a(14) =6125625a(15) =9150625a(16) =13176900a(17) =18974736a(18) =26501904a(19) =37015056a(20) =50381604a(21) =68574961a(22) =91298025a(23) =121550625a(24) =158760000a(25) =207360000