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Number of tilings of a 6 X n rectangle using dominoes and straight (3 X 1) trominoes.
2

%I #8 Dec 07 2012 12:45:04

%S 1,2,30,472,5624,82634,1143834,15859323,223026907,3105936858,

%T 43427618185,606962113407,8477372675760,118475405895601,

%U 1655302050975409,23128348583334118,323168394713538001,4515400902297318144,63091618970759626487,881547198837947075202

%N Number of tilings of a 6 X n rectangle using dominoes and straight (3 X 1) trominoes.

%H Alois P. Heinz, <a href="/A219869/b219869.txt">Table of n, a(n) for n = 0..300</a>

%e a(1) = 2, because there are 2 tilings of a 6 X 1 rectangle using dominoes and straight (3 X 1) trominoes:

%e ._. ._.

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%Y Column k=6 of A219866.

%K nonn

%O 0,2

%A _Alois P. Heinz_, Nov 30 2012