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A249762
Number of tilings of a 5 X n rectangle using n pentominoes of shapes F, I, L.
9
1, 1, 3, 5, 13, 50, 133, 360, 875, 2254, 6336, 17331, 47199, 124476, 330344, 889454, 2400961, 6485476, 17392906, 46616158, 125153478, 336529923, 905611165, 2434088873, 6539233985, 17567977887, 47214493386, 126927551197, 341177175540, 916960655233
OFFSET
0,3
LINKS
FORMULA
a(n) ~ c * d^n, where d = 2.6877447474867836174937272605197376719631593933016281800670782370745298422..., c = 0.3236150736074998563483897952085529328299218049725560430481595704054051228... (1/d is the root of the denominator, see g.f.). - Vaclav Kotesovec, May 19 2015
EXAMPLE
a(4) = 13:
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|_|_|_|_| (1) |___|___| (2) |_|___|_| (2)
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|_| | | | |_| |_| | |_| | |_|
|___|_|_| (4) |___|___| (2) |___|___| (2) .
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Dec 03 2014
STATUS
approved