%I #8 May 07 2019 15:09:52
%S 0,4,120,6912,631680,84211200,15432560640,3722677862400,
%T 1143584003358720,435902085306777600,201889940373209088000,
%U 111673403387053395148800,72713691524377589317632000,55052849030095232395798118400,47957058157063329359371173888000
%N Number of (undirected) Hamiltonian paths in the n-cocktail party graph.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CocktailPartyGraph.html">Cocktail Party Graph</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HamiltonianPath.html">Hamiltonian Path</a>
%F a(n) = A007060(n)/2.
%Y Cf. A007060.
%K nonn,easy
%O 1,2
%A _Eric W. Weisstein_, May 06 2019