%I A137886
%S A137886 12,144,3840,138240,6804000,436504320,35417088000,3546005299200,429451518988800,
%T A137886 61883150757120000,10463789706751180800
%N A137886 Number of (directed) Hamiltonian paths in the n-crown graph.
%H A137886 Max Alekseyev, <a href="http://www.cse.sc.edu/~maxal/gpscripts/">PARI/
               GP Scripts for Miscellaneous Math Problems</a>
%H A137886 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               HamiltonianPath.html">Hamiltonian Path</a>
%H A137886 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               CrownGraph.html">Crown Graph</a>
%o A137886 (PARI) { A137886(n) = nhp( matrix(2*n,2*n,i,j, if(min(i,j)<=n && max(i,
               j)>n && abs(j-i)!=n, 1, 0)) ) }
%Y A137886 Sequence in context: A123237 A143248 A138444 this_sequence A097303 A067219 
               A075619
%Y A137886 Adjacent sequences: A137883 A137884 A137885 this_sequence A137887 A137888 
               A137889
%K A137886 nonn,more
%O A137886 3,1
%A A137886 E. W. Weisstein (eric(AT)weisstein.com), Feb 20, 2008
%E A137886 More terms from Max Alekseyev (maxale(AT)gmail.com), Feb 13 2009