Ways to tile a 5 X (2n+1) floor with tatami mats, including one monomer.

Terms

a(0) =3a(1) =18a(2) =10a(3) =8a(4) =18a(5) =24a(6) =32a(7) =52a(8) =68a(9) =100a(10) =142a(11) =196a(12) =280a(13) =388a(14) =542a(15) =756a(16) =1046a(17) =1452a(18) =2006a(19) =2768a(20) =3816a(21) =5248a(22) =7212a(23) =9896a(24) =13562a(25) =18568a(26) =25392a(27) =34692a(28) =47354a(29) =64580