%I #18 Dec 24 2016 11:14:43
%S 0,0,0,25506,1759280998,854818404562894,3588226034666378581610,
%T 138311081613064367684548901556,
%U 50272239752141442901464758051467073726,174927321882862834702052846250836696969014873138,5889117928937174007411459040006660524033737246962655301188
%N Number of fault-free domino tilings (or dimer coverings) of a 2n X 2n square.
%C Enumerates a subclass of the things counted by A004003.
%C "Fault-free" means that every straight line through the interior of the square hits the interior of some domino.
%H Xu Mingkuan, <a href="/A124997/b124997.txt">Table of n, a(n) for n = 1..12</a>
%Y Cf. A004003.
%K nonn
%O 1,4
%A _Don Knuth_, Jun 26 2008
%E a(7) from _Alois P. Heinz_, Oct 19 2015
%E a(8)-a(11) from _Xu Mingkuan_, Dec 23 2016