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%I #11 Jul 30 2015 22:29:39
%S 1,20,263,2902,29289,281472,2630731,24196634,220500797,1998686404,
%T 18061169919,162923877246,1468215185425,13223572329416,
%U 119060866122227,1071793518338338,9647378871105573,86832630229860108
%N Expansion of 1/((1-2x)(1-4x)(1-5x)(1-9x)).
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (20, -137, 382, -360).
%F a(0)=1, a(1)=20, a(2)=263, a(3)=2902, a(n)=20*a(n-1)-137*a(n-2)+ 382*a(n-3)- 360*a(n-4). [_Harvey P. Dale_, Dec 08 2011]
%F a(n) = -4*2^n/21 +32*4^n/5 -125*5^n/12 +729*9^n/140. - _R. J. Mathar_, Jun 20 2013
%t CoefficientList[Series[1/((1-2x)(1-4x)(1-5x)(1-9x)),{x,0,30}],x] (* or *) LinearRecurrence[{20,-137,382,-360},{1,20,263,2902},30] (* _Harvey P. Dale_, Dec 08 2011 *)
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_.
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