%I #13 Jun 13 2015 00:49:05
%S 0,1,-5,-42,-22,575,1677,-3332,-27740,-23859,259055,832370,-981714,
%T -10980437,-13342175,85437240,319499912,-192522535,-3642631389,
%U -5753449394,24313788850,108290637399,-13811840779,-1096315586380,-2152355798868,6240751807525
%N The Gegenbauer Polynomial of index n, order 1, evaluated at x=1/3 and multiplied by n*3^n/2.
%H Alois P. Heinz, <a href="/A025173/b025173.txt">Table of n, a(n) for n = 0..1000</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Gegenbauer_polynomials">Gegenbauer Polynomials</a>
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-22,36,-81).
%F G.f.: ( x-9*x^2 ) / (1-2*x+9*x^2)^2 . - _R. J. Mathar_, Feb 05 2013
%p a:= n-> (<<0|1|0|0>, <0|0|1|0>, <0|0|0|1>, <-81|36|-22|4>>^n. <<0, 1, -5, -42>>)[1, 1]: seq(a(n), n=0..50); # _Alois P. Heinz_, Feb 05 2013
%t Table[ n/2 3^n GegenbauerC[ n, 1, 1/3 ], {n, 24} ]
%K sign
%O 0,3
%A _Wouter Meeussen_
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