Number of 2 X n 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

Terms

a(0) =4a(1) =16a(2) =36a(3) =81a(4) =169a(5) =324a(6) =625a(7) =1156a(8) =2116a(9) =3844a(10) =6889a(11) =12321a(12) =21904a(13) =38809a(14) =68644a(15) =121104a(16) =213444a(17) =375769a(18) =660969a(19) =1162084a(20) =2042041a(21) =3587236a(22) =6300100a(23) =11062276a(24) =19421649a(25) =34093921a(26) =59845696a(27) =105042001a(28) =184362084a(29) =323568144