A265106 Expansion of (x^5-x^4-2*x^3+x^2-x)/(-x^4+x^3-2*x^2+3*x-1).
0, 1, 2, 6, 16, 36, 80, 178, 394, 870, 1920, 4236, 9344, 20610, 45458, 100262, 221136, 487732, 1075728, 2372594, 5232922, 11541574, 25455744, 56144412, 123830400, 273116546, 602377506, 1328585414, 2930287376, 6462952260, 14254489936, 31439267250, 69341486762
Offset: 0
Links
- Colin Barker, Table of n, a(n) for n = 0..1000
- M. Diepenbroek, M. Maus, A. Stoll, Pattern Avoidance in Reverse Double Lists, Preprint 2015. See Table 3.
- Index entries for linear recurrences with constant coefficients, signature (3,-2,1,-1).
Programs
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Mathematica
CoefficientList[Series[(x^5-x^4-2x^3+x^2-x)/(-x^4+x^3-2x^2+3x-1),{x,0,40}],x] (* or *) LinearRecurrence[{3,-2,1,-1},{0,1,2,6,16,36},40] (* Harvey P. Dale, Feb 05 2019 *) -
PARI
concat(0, Vec(x*(1-x+2*x^2+x^3-x^4)/((1-x)*(1-2*x-x^3)) + O(x^50))) \\ Colin Barker, Apr 12 2016
Formula
a(n) = 3*a(n-1)-2*a(n-2)+a(n-3)-a(n-4) for n>5. - Colin Barker, Apr 12 2016
a(n) = 2*a(n-1) + a(n-3) + 2 for n>4. - Greg Dresden, Feb 09 2020