Number of tatami tilings of a 5 X n grid (with monomers allowed).

Terms

a(0) =1a(1) =8a(2) =68a(3) =90a(4) =126a(5) =178a(6) =325a(7) =584a(8) =1165a(9) =2030a(10) =3619a(11) =6080a(12) =10987a(13) =19362a(14) =35477a(15) =62360a(16) =111837a(17) =195614a(18) =350707a(19) =619568a(20) =1112315a(21) =1967090a(22) =3514597a(23) =6214984a(24) =11093549a(25) =19664558a(26) =35090115a(27) =62247552a(28) =110934699a(29) =196859394