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%I #6 May 28 2016 18:36:22
%S 85,1364,21840,349504,5592320,89478144,1431654400,22906486784,
%T 366503854080,5864061927424,93824991887360,1501199874392064,
%U 24019198007050240,384307168179912704,6148914691147038720
%N a(n) = 20*a(n-1) - 64*a(n-2) for n > 1; a(0) = 85, a(1) = 1364.
%C Related to Reverse and Add trajectory of 318 in base 4: A075153(6*n+5) = 240*a(n).
%C lim_{n -> infinity} a(n)/a(n-1) = 16.
%H G. C. Greubel, <a href="/A166917/b166917.txt">Table of n, a(n) for n = 0..500</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (20, -64).
%F a(n) = (256*16^n - 4^n)/3.
%F G.f.: (85 - 336*x)/((1-4*x)*(1-16*x)).
%F E.g.f.: (1/3)*(256*exp(16*x) - exp(4*x)). - _G. C. Greubel_, May 28 2016
%t LinearRecurrence[{20,-64}, {85, 1364}, 50] (* _G. C. Greubel_, May 28 2016 *)
%o (PARI) {m=15; v=concat([85, 1364], vector(m-2)); for(n=3, m, v[n]=20*v[n-1]-64*v[n-2]); v}
%Y Cf. A075153, A166912, A166913, A166914, A166915, A166916, A166927, A166965, A166984.
%K nonn
%O 0,1
%A _Klaus Brockhaus_, Oct 27 2009
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