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%I #8 Sep 19 2017 10:23:20
%S 0,96,384,1536,6144,24576,98304,393216,1572864,6291456,25165824,
%T 100663296,402653184,1610612736,6442450944,25769803776,103079215104,
%U 412316860416,1649267441664,6597069766656,26388279066624,105553116266496,422212465065984,1688849860263936
%N Number of 5-cycles in the n-Sierpinski tetrahedron graph.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GraphCycle.html">Graph Cycle</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SierpinskiTetrahedronGraph.html">Sierpinski Tetrahedron Graph</a>
%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (4).
%F a(n) = 6*4^n = A002023(n) for n > 1.
%F a(n) = 4*a(n-1) for n > 2.
%F G.f.: 96*x^/(1 - 4*x).
%t Table[If[n == 1, 0, 6 4^n], {n, 20}]
%t Join[{0}, LinearRecurrence[{4}, {96}, 20]]
%t CoefficientList[Series[96 x/(1 - 4 x), {x, 0, 20}], x]
%Y Cf. A002023 (6*4^n).
%Y Cf. A292540 (3-cycles), A292542 (4-cycles), A292545 (6-cycles).
%K nonn,easy
%O 1,2
%A _Eric W. Weisstein_, Sep 18 2017