|
%I #12 Sep 05 2021 19:14:26
%S 1,4,21,54,343,1225,7104,31777,169952,819260,4234749,21008157,
%T 107087889,536982808,2721665059,13704483996,69301052416,349520578291,
%U 1765820428959,8911657997748,45005845549969,227191526564923,1147192132487813,5791672997769659
%N Number of tilings of a 6 X n rectangle using integer-sided rectangular tiles of equal area.
%C a(n+1)/a(n) tends to r = 5.048917339522305313522214407..., where r is the largest root of 1-5*x+6*x^2-x^3. - _Vaclav Kotesovec_, Dec 21 2012
%H Alois P. Heinz, <a href="/A220772/b220772.txt">Table of n, a(n) for n = 0..500</a>
%e a(1) = 4:
%e ._. ._. ._. ._.
%e | | | | | | |_|
%e | | | | |_| |_|
%e | | |_| | | |_|
%e | | | | |_| |_|
%e | | | | | | |_|
%e |_| |_| |_| |_|
%Y Column k=6 of A220777.
%K nonn
%O 0,2
%A _Alois P. Heinz_, Dec 19 2012
|
