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Number of tilings of an 8 X n rectangle using 2*n copies of the disconnected shape [oo__oo].
5

%I #22 Nov 15 2023 17:37:14

%S 1,1,1,1,1,1,5,11,36,69,112,163,260,425,897,1845,3910,7524,13683,

%T 23675,41741,74882,141758,272059,525251,992342,1841482,3361173,

%U 6142594,11291891,21037446,39459473,74198937,138852912,258417206,478462336,885161178,1640011925

%N Number of tilings of an 8 X n rectangle using 2*n copies of the disconnected shape [oo__oo].

%D D. E. Knuth: The Art of Computer Programming, Volume 4, Pre-fascicle 5C, Dancing Links, 2018.

%H Alois P. Heinz, <a href="/A323352/b323352.txt">Table of n, a(n) for n = 0..3712</a>

%H Alois P. Heinz, <a href="/A323352/a323352.txt">G.f. for A323352</a>

%H D. E. Knuth, <a href="https://www.youtube.com/watch?v=_cR9zDlvP88">Dancing Links</a>, 24th Annual Christmas Lecture, Stanfordonline video (2018)

%H D. E. Knuth, <a href="https://arxiv.org/abs/cs/0011047">Dancing Links</a>, arXiv:cs/0011047 [cs.DS], 2000.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Dancing_Links">Dancing Links</a>

%F G.f.: see link above.

%F a(n) ~ c * d^n, where d = 1.860082974490657614690253062429801614977133563402428780098509287692125963... and c = 0.175453010088369049748675582204204705345337476531410983285862441563015... - _Vaclav Kotesovec_, Jan 15 2019

%e a(6) = 5:

%e .

%e ._._._._._._. .___._._.___. .___._._.___.

%e | | | | | | | |___| | |___| |___| | |___|

%e |_|_|_|_|_|_| |___|_|_|___| |___|_|_|___|

%e | | | | | | | |___| | |___| | | | | | | |

%e |_|_|_|_|_|_| |___|_|_|___| |_|_|_|_|_|_|

%e | | | | | | | |___| | |___| |___| | |___|

%e |_|_|_|_|_|_| |___|_|_|___| |___|_|_|___|

%e | | | | | | | |___| | |___| | | | | | | |

%e |_|_|_|_|_|_| |___|_|_|___| |_|_|_|_|_|_|

%e .

%e ._._._._._._. .___._._.___.

%e | | | | | | | |___| | |___|

%e |_|_|_|_|_|_| | | |_|_| | |

%e |___| | |___| |_|_| | |_|_|

%e |___|_|_|___| |___|_|_|___|

%e | | | | | | | |___| | |___|

%e |_|_|_|_|_|_| | | |_|_| | |

%e |___| | |___| |_|_| | |_|_|

%e |___|_|_|___| |___|_|_|___|

%e .

%Y Cf. A320437, A323423, A323483, A322473.

%K nonn,easy

%O 0,7

%A _Alois P. Heinz_, Jan 12 2019