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%I #16 Aug 08 2019 18:53:32
%S 1,3,9,21,45,87,159,273,450,712,1092,1626,2364,3360,4686,6420,8661,
%T 11517,15121,19617,25179,31995,40287,50295,62298,76596,93534,113482,
%U 136860,164118,195762,232332,274431,322701,377853,440643,511903,592515,683445,785715
%N Expansion of (1+x^3)/((1-x)^3*(1-x^2)^3*(1-x^3)).
%D Y. Teranishi, Linear Diophantine equations and invariant theory of matrices, in Commutative algebra and combinatorics (Kyoto, 1985), pp. 259-275, Adv. Stud. Pure Math., 11, North-Holland, Amsterdam, 1987.
%H <a href="/index/Mo#Molien">Index entries for Molien series</a>
%H <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (4,-4,-3,6,0,0,-6,3,4,-4,1).
%F G.f.: ( -1+x-x^2 ) / ( (1+x+x^2)*(1+x)^2*(x-1)^7 ). - _R. J. Mathar_, Dec 18 2014
%F 81*a(n) = 2*A099837(n+3) +(134946*n +22680*n^3 +77688*n^2 +3690*n^4 +324*n^5 +12*n^6 +87625)/1280 +(-1)^n*243 *(9+2*n)/256 . - _R. J. Mathar_, Dec 17 2017
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, May 23 2005