Number of n X 2 binary arrays with each 1 adjacent to exactly two 0's.

Terms

a(0) =1a(1) =7a(2) =10a(3) =23a(4) =49a(5) =98a(6) =209a(7) =431a(8) =898a(9) =1871a(10) =3889a(11) =8098a(12) =16849a(13) =35063a(14) =72970a(15) =151847a(16) =316001a(17) =657602a(18) =1368481a(19) =2847839a(20) =5926402a(21) =12332959a(22) =25665121a(23) =53409602a(24) =111146401a(25) =231297767a(26) =481335050a(27) =1001667383a(28) =2084488849a(29) =4337860898