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%I #11 Dec 21 2014 10:59:30
%S 9,632025,23057815104,763341471963225,24743382596536452489,
%T 797880028172050676793600,25694231385152383926116001849,
%U 827147402338052897443922764419225,26625078176206788678765153788526329856
%N Number of spanning trees in C_9 X P_n.
%H Alois P. Heinz, <a href="/A174001/b174001.txt">Table of n, a(n) for n = 1..70</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CycleGraph.html">Cycle Graph</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PathGraph.html">Path Graph</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SpanningTree.html">Spanning Tree</a>
%F See program.
%p a:= n-> 9* (Matrix([[0, 1, 265, 50616, 9209545, 1658090689, 297747101520, 53431400864569, 9586723471888105][1+abs(i)]$i=-7..8]). Matrix(16, (i, j)-> if i=j-1 then 1 elif j=1 then [[-427427424, 327381265, -146975161, 38357160, -5699687, 457655, -17736, 265, -1][1+abs(k)]$k=-7..8][i] else 0 fi)^n)[1, 8]^2: seq(a(n), n=1..20);
%Y 9th column of A173958.
%Y Cf. A000012, A001542, A003690, A003753, A003733, A158880, A158898.
%K nonn,easy
%O 1,1
%A _Alois P. Heinz_, Nov 26 2010