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%I #8 Sep 04 2021 20:09:22
%S 17,81,405,2025,10125,50625,253125,1265625,6328125,31640625,158203125,
%T 791015625,3955078125,19775390625,98876953125,494384765625,
%U 2471923828125,12359619140625,61798095703125,308990478515625,1544952392578125,7724761962890625
%N Number of dominating sets in the n-alkane graph.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AlkaneGraph.html">Alkane Graph</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DominatingSet.html">Dominating Set</a>
%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (5).
%F a(n) = 81*5^(n-2) for n > 1.
%F G.f.: x*(4*x - 17)/(5*x - 1).
%F E.g.f.: (81*exp(5*x) + 20*x - 81)/25. - _Stefano Spezia_, Sep 04 2021
%t Join[{17}, LinearRecurrence[{5}, {81}, 20]]
%t CoefficientList[Series[(4 x - 17)/(5 x - 1), {x, 0, 20}], x]
%Y Cf. A180148, A228602, A347478.
%K nonn,easy
%O 1,1
%A _Eric W. Weisstein_, Sep 04 2021