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a(n) = (-1)^(n-1)*n*(4n^2-5)^2.
1

%I #19 Mar 24 2020 19:18:45

%S 1,-242,2883,-13924,45125,-115926,255367,-504008,915849,-1560250,

%T 2523851,-3912492,5853133,-8495774,12015375,-16613776,22521617,

%U -30000258,39343699,-50880500

%N a(n) = (-1)^(n-1)*n*(4n^2-5)^2.

%C These are the partial sums of the alternating series of odd fifth powers beginning with 1. See A016757.

%H G. C. Greubel, <a href="/A165935/b165935.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (-6,-15,-20,-15,-6,-1).

%F G.f.: x*(1-236*x+1446*x^2-236*x^3+x^4) / (1+x)^6. - _R. J. Mathar_, Nov 27 2011

%F E.g.f.: x*(1 - 120*x + 360*x^2 - 160*x^3 + 16*x^4)*exp(-x). - _Ilya Gutkovskiy_, Apr 17 2016

%t Table[(-1)^(n - 1)*n*(4*n^2 - 5)^2, {n, 1, 50}] (* _G. C. Greubel_, Apr 18 2016 *)

%t LinearRecurrence[{-6,-15,-20,-15,-6,-1},{1,-242,2883,-13924,45125,-115926},20] (* _Harvey P. Dale_, Mar 24 2020 *)

%o (PARI) vector(100, n, (-1)^(n-1)*n*(4*n^2-5)^2) \\ _Altug Alkan_, Apr 18 2016

%Y Cf. A016757.

%K easy,sign

%O 1,2

%A Richard L. Peterson (rl_pete(AT)yahoo.com), Oct 01 2009