Number of n X 2 0..1 arrays with each 1 adjacent to 2 or 3 king-move neighboring 1s.

Terms

a(0) =1a(1) =6a(2) =15a(3) =28a(4) =90a(5) =281a(6) =737a(7) =2095a(8) =6268a(9) =17965a(10) =51360a(11) =149540a(12) =433577a(13) =1250789a(14) =3620541a(15) =10489538a(16) =30345263a(17) =87801224a(18) =254176114a(19) =735652561a(20) =2128923525a(21) =6161699035a(22) =17833776016a(23) =51613806741a(24) =149380609556a(25) =432342904636