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%I #7 Mar 31 2012 10:32:24
%S 3,0,3,1,9,6,45,42,279,320,1977,2610,15306,22404,126300,200158,
%T 1093515,1846314,9830547,17481864
%N Number of ways a loop can cross three roads meeting in a Y n times.
%C The Mercedes-Benz problem: closed meanders crossing a Y.
%H Anonymous, <a href="/A078105/a078105.a.gif">Illustration for a(3) = 1</a>
%e With three crossings the loop must cut each road exactly once, so a(3) = 1.
%Y Similar to A078104, but without the constraint of touching the (-, -) quadrant.
%K nonn
%O 0,1
%A _N. J. A. Sloane_ and _Jon Wild_, Aug 25 2003
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