A372221 Number of tilings of a 5 X n rectangle using n pentominoes of shapes T, W, I, X.
1, 1, 1, 1, 1, 2, 3, 6, 9, 12, 16, 21, 41, 66, 106, 156, 219, 364, 558, 930, 1444, 2191, 3515, 5361, 8737, 13661, 21478, 34397, 53528, 86137, 135294, 215432, 345081, 546705, 879212, 1395476, 2239086, 3596427, 5767656, 9312008, 14949738, 24163742, 39045229
Offset: 0
Examples
a(7) = 6: ._____________. ._____________. ._____________. | |_________| | | | | | | | | | |_________| | | | .___| |___. | | | | | | | | | |_________| | | |_| ._| |_. |_| | | | | | | | | |_________| | | | ._|_____|_. | | | | | | | | | |_________| | | |_|_________|_| |_|_|_|_|_|_|_| |_________|_|_| ._____________. ._____________. ._____________. | |_________| | | |_________| | | | |_________| |_. |_. ._| ._| | |_________| | | | |_________| | |___| |___| | | |_________| | | | |_________| | .___|_|___. | | |_________| | | | |_________| |_|_________|_| |_|_________|_| |_|_|_________| .
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..4472
- Alois P. Heinz, G.f. for A372221
- Wikipedia, Pentomino
- Index entries for linear recurrences with constant coefficients, order 139.