Number of tilings of a 5 X n rectangle using n pentominoes of shapes T, I, P.

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =17a(5) =78a(6) =199a(7) =638a(8) =1865a(9) =5332a(10) =17250a(11) =50877a(12) =156787a(13) =475348a(14) =1423432a(15) =4367178a(16) =13182353a(17) =40122074a(18) =121916294a(19) =369052634a(20) =1122475534a(21) =3403574961a(22) =10335095973a(23) =31385295907a(24) =95218937465a(25) =289154182737a(26) =877572289140