The number of tilings of a 9 X (2n) floor with 2 X 3 hexominoes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =5a(4) =11a(5) =19a(6) =45a(7) =105a(8) =219a(9) =475a(10) =1061a(11) =2313a(12) =5027a(13) =11035a(14) =24173a(15) =52793a(16) =115499a(17) =252827a(18) =552981a(19) =1209545a(20) =2646419a(21) =5789563a(22) =12664925a(23) =27706873a(24) =60614235a(25) =132602171a(26) =290087749a(27) =634616521a(28) =1388325507a(29) =3037181147