%I #37 Jan 25 2022 01:46:07
%S 0,0,8,0,82,744,6378,31088,189688,1213112,6683852,36486328,201282470,
%T 1083585304,5706117458,29819231288,154430502724,790787799376,
%U 4014945695196,20241304810488,101336136490228,504096313001272,2493533648002492,12270473056485396
%N Number of (undirected) Hamiltonian paths on the 4 X n knight graph.
%D Kraitchik, M. Mathematical Recreations. New York: W. W. Norton, p. 263, 1942.
%H Andrew Howroyd, <a href="/A079137/b079137.txt">Table of n, a(n) for n = 1..500</a>
%H George Jellis, <a href="http://web.archive.org/web/20070622154018/http://home.freeuk.net/ktn/4a.htm">Knight's tour diagrams</a>
%H Colin Rose, <a href="http://www.tri.org.au/knightframe.html">Knight's tours</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HamiltonianPath.html">Hamiltonian Path</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/KnightGraph.html">Knight Graph</a>
%Y See A079312 for 4 times these numbers, A123935 for twice these numbers, A123936 for these numbers halved.
%Y Cf. A169696, A083386, A165134, A328341.
%K nonn
%O 1,3
%A _Eric W. Weisstein_, Dec 28 2002
%E More terms from André Pönitz (poenitz(AT)htwm.de), Jun 11 2003
%E Edited by _N. J. A. Sloane_, Oct 30 2006, following suggestions from Colin Rose
%E Terms a(22) and beyond from _Andrew Howroyd_, Jul 01 2017