%I #17 Aug 26 2019 12:17:40
%S 0,1,2,6,24,102,414,1598,5982,22102,81442,300562,1111638,4117382,
%T 15259738,56561346,209629750,776850166,2878660394,10666717442,
%U 39524757670,146456879830,542691221946,2010931777154,7451478924278,27611353095414,102313463160906
%N Expansion of (x-7*x^2+19*x^3-21*x^4+10*x^5-6*x^6) / (1-9*x+31*x^2-53*x^3+44*x^4-16*x^5+6*x^6).
%C Number of irreducible indecomposable pop-stack permutations of a certain type.
%H Colin Barker, <a href="/A078486/b078486.txt">Table of n, a(n) for n = 0..1000</a>
%H M. D. Atkinson and T. Stitt, <a href="http://www.cs.otago.ac.nz/staffpriv/mike/Papers/WreathProduct/Wreathpaper.pdf">Restricted permutations and the wreath product</a>, Preprint, 2002.
%H M. D. Atkinson and T. Stitt, <a href="http://dx.doi.org/10.1016/S0012-365X(02)00443-0">Restricted permutations and the wreath product</a>, Discrete Math., 259 (2002), 19-36.
%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (9,-31,53,-44,16,-6).
%t CoefficientList[Series[(x-7x^2+19x^3-21x^4+10x^5-6x^6)/(1-9x+31x^2- 53x^3+ 44x^4- 16x^5+6x^6),{x,0,40}],x] (* _Harvey P. Dale_, Aug 26 2019 *)
%o (PARI) concat(0, Vec((x-7*x^2+19*x^3-21*x^4+10*x^5-6*x^6)/(1-9*x+31*x^2-53*x^3+44*x^4-16*x^5+6*x^6) + O(x^50))) \\ _Colin Barker_, May 27 2016
%K nonn,easy
%O 0,3
%A _N. J. A. Sloane_, Jan 04 2003
%E Replaced definition with g.f. given by Atkinson and Stitt (2002). - _N. J. A. Sloane_, May 24 2016
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