Number of (n+2)X3 binary arrays avoiding patterns 001 and 111 in rows and columns.

Terms

a(0) =98a(1) =257a(2) =611a(3) =1326a(4) =2815a(5) =5718a(6) =11362a(7) =22164a(8) =42507a(9) =80633a(10) =151352a(11) =281811a(12) =521224a(13) =958418a(14) =1754004a(15) =3196693a(16) =5805401a(17) =10510754a(18) =18978585a(19) =34187852a(20) =61457038a(21) =110271668a(22) =197530737a(23) =353309613a(24) =631087988a(25) =1125880395a(26) =2006365746