A078486 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).

0, 1, 2, 6, 24, 102, 414, 1598, 5982, 22102, 81442, 300562, 1111638, 4117382, 15259738, 56561346, 209629750, 776850166, 2878660394, 10666717442, 39524757670, 146456879830, 542691221946, 2010931777154, 7451478924278, 27611353095414, 102313463160906

Offset

0,3

Comments

Number of irreducible indecomposable pop-stack permutations of a certain type.

Links

Colin Barker, Table of n, a(n) for n = 0..1000

M. D. Atkinson and T. Stitt, Restricted permutations and the wreath product, Preprint, 2002.

M. D. Atkinson and T. Stitt, Restricted permutations and the wreath product, Discrete Math., 259 (2002), 19-36.

Index entries for linear recurrences with constant coefficients, signature (9,-31,53,-44,16,-6).

Mathematica

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 *)

Prog

(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

Crossrefs

Sequence in context: A141253 A306672 A324063 * A352364 A129817 A230797

Adjacent sequences: A078483 A078484 A078485 * A078487 A078488 A078489

Keyword

nonn,easy

Author

N. J. A. Sloane, Jan 04 2003

Extensions

Replaced definition with g.f. given by Atkinson and Stitt (2002). - N. J. A. Sloane, May 24 2016

Status

approved