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Number of tilings of a 20 X n rectangle using 2*n copies of the disconnected shape [ooooo_____ooooo].
5

%I #25 Nov 15 2023 17:39:06

%S 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,8,17,28,41,56,144,240,344,456,576,712,

%T 856,1008,1168,1336,1625,2069,2708,3588,4761,7705,12796,20588,31689,

%U 46761,73081,111213,162897,229969,314361,421416,555737,723341,931537,1189140

%N Number of tilings of a 20 X n rectangle using 2*n copies of the disconnected shape [ooooo_____ooooo].

%H Alois P. Heinz, <a href="/A322473/b322473.txt">Table of n, a(n) for n = 0..7011</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>

%Y Cf. A320437, A323352, A323483, A323423.

%K nonn

%O 0,16

%A _Alois P. Heinz_, Jan 16 2019