%I #23 Jun 28 2023 20:37:09
%S 0,2,6,24,86,320,1176,4340,15994,58970,217388,801426,2954496,10891960,
%T 40153904,148030026,545722366,2011841328,7416784934,27342464080,
%U 100799786752,371605023956,1369946288898,5050396829138
%N Number of Hamiltonian cycles in D_4 X P_n.
%D F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129-154.
%H F. Faase, <a href="http://www.iwriteiam.nl/Cpaper.zip">On the number of specific spanning subgraphs of the graphs G X P_n</a>, Preliminary version of paper that appeared in Ars Combin. 49 (1998), 129-154.
%H F. Faase, <a href="http://www.iwriteiam.nl/counting.html">Counting Hamiltonian cycles in product graphs</a>
%H F. Faase, <a href="http://www.iwriteiam.nl/Cresults.html">Results from the counting program</a>
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3, 3, -2, 1).
%F a(n) = 3*a(n-1) + 3*a(n-2) - 2*a(n-3) + a(n-4), n>4.
%F G.f.: 2*x^2/(1-3*x-3x^2+2*x^3-x^4). - _R. J. Mathar_, Dec 16 2008
%K nonn
%O 1,2
%A _Frans J. Faase_, Mar 15 1996