Number of tilings of a 5 X n rectangle using n pentominoes of any but the X shape.

A247775

Number of tilings of a 5 X n rectangle using n pentominoes of any but the X shape.

Terms

    a(0) =1a(1) =1a(2) =5a(3) =55a(4) =493a(5) =3930a(6) =27207a(7) =207118a(8) =1622723a(9) =12544364a(10) =95912510a(11) =732066083a(12) =5616480627a(13) =43128778000a(14) =330817187318

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