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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). 1
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 (list; graph; refs; listen; history; text; internal format)
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 * A129817 A230797 A128652

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

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Last modified September 19 03:31 EDT 2021. Contains 347550 sequences. (Running on oeis4.)