A158898 - OEIS

%I #10 Feb 07 2017 10:36:10

%S 7,35287,113742727,347251215703,1050773495363767,3174564739209417463,

%T 9588099190533549457408,28957256518828921149989143,

%U 87453655435340440175476698487,264117827347202707929587420182327

%N Number of spanning trees in C_7 X P_n.

%H Alois P. Heinz, <a href="/A158898/b158898.txt">Table of n, a(n) for n = 1..288</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>

%F See program.

%p a:= n-> 7* (Matrix([222727, 4031, 71, 1, 0, -1, -71, -4031]). Matrix(8, (i,j)-> if i=j-1 then 1 elif j=1 then [71, -952, 3976, -6384, 3976, -952, 71, -1][i] else 0 fi)^n)[1,5]^2: seq(a(n), n=1..15);

%Y 7th column of A173958.

%Y Cf. A001353, A003690, A003753, A003733, A158880.

%K nonn,easy

%O 1,1

%A _Alois P. Heinz_, Mar 29 2009