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A251617
Number of tilings of a 5 X n rectangle using n pentominoes of shapes F, I, L, U.
3
1, 1, 3, 5, 19, 74, 219, 628, 1749, 5486, 17448, 53383, 160169, 479908, 1468366, 4512092, 13782535, 41855766, 127112554, 387469920, 1182800866, 3606789463, 10983721059, 33445214911, 101911804705, 310658892951, 946813182854, 2884825285301, 8789233684468
OFFSET
0,3
LINKS
Wikipedia, Pentomino
EXAMPLE
a(4) = 19 = 13 + 4 + 2 = A249762(4) + 4 + 2:
._______. ._______.
|_____. | | ._____|
| | ._|_| |_| ._. |
| | |_. | | |_| |_|
| |___| | |_____| |
|___|___| (4) |_______| (2) .
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Dec 05 2014
STATUS
approved