Number of tilings of a 10 X n rectangle using 2n pentominoes of shape L.

Terms

a(0) =1a(1) =0a(2) =4a(3) =0a(4) =16a(5) =32a(6) =76a(7) =384a(8) =386a(9) =2976a(10) =3952a(11) =20520a(12) =41104a(13) =136160a(14) =393624a(15) =1027072a(16) =3412146a(17) =8470840a(18) =27988904a(19) =74155272a(20) =230939032a(21) =655493408a(22) =1942645984a(23) =5765577688a(24) =16807041186a(25) =50708538824a(26) =148118970352a(27) =446903215688