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%I #20 Jan 04 2023 03:03:38
%S 1,-8,15,-112,209,-1560,2911,-21728,40545,-302632,564719,-4215120,
%T 7865521,-58709048,109552575,-817711552,1525870529,-11389252680,
%U 21252634831,-158631825968,296011017105,-2209456310872,4122901604639,-30773756526240,57424611447841
%N a(2*n) = A028230(n), a(2*n+1) = -A067900(n+1).
%C See A110293.
%H Colin Barker, <a href="/A110294/b110294.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,14,0,-1).
%F G.f.: (1-8*x+x^2) / ((1-4*x+x^2)*(1+4*x+x^2)).
%F a(n) = 14*a(n-2) - a(n-4) for n>3. - _Colin Barker_, Nov 01 2016
%F a(n) = (3*(-1)^n - 1)*A001353(n+1)/2. - _R. J. Mathar_, Sep 11 2019
%p seriestolist(series((1-8*x+x^2)/((x^2-4*x+1)*(x^2+4*x+1)), x=0,25));
%t CoefficientList[Series[(1-8x+x^2)/((1-4x+x^2)(1+4x+x^2)), {x, 0, 24}], x] (* _Michael De Vlieger_, Nov 01 2016 *)
%o (PARI) Vec((1-8*x+x^2)/((1-4*x+x^2)*(1+4*x+x^2)) + O(x^30)) \\ _Colin Barker_, Nov 01 2016
%o (Magma) [(3*(-1)^n-1)*Evaluate(ChebyshevSecond(n+1), 2)/2: n in [0..40]]; // _G. C. Greubel_, Jan 04 2023
%o (SageMath) [(3*(-1)^n-1)*chebyshev_U(n,2)/2 for n in range(41)] # _G. C. Greubel_, Jan 04 2023
%Y Cf. A001353, A001570, A011943, A028230, A067900, A110293.
%K easy,sign
%O 0,2
%A _Creighton Dement_, Jul 18 2005
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