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

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =8a(6) =14a(7) =21a(8) =37a(9) =63a(10) =122a(11) =221a(12) =374a(13) =656a(14) =1147a(15) =2066a(16) =3699a(17) =6477a(18) =11407a(19) =20099a(20) =35656a(21) =63323a(22) =111775a(23) =197352a(24) =348556a(25) =616560a(26) =1091570a(27) =1929721a(28) =3410509a(29) =6028021