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A106804 Expansion of g.f.: x*(2 - 9*x - 4*x^2)/((1 - 5*x + x^2)*(1 - 5*x - x^2)). 1
0, 2, 11, 56, 285, 1452, 7406, 37816, 193295, 989002, 5065051, 25963276, 133199780, 683904902, 3514119571, 18069536436, 92975574865, 478701242652, 2466137174466, 12711910214796, 65558648361175, 338267429484502 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
G.f.: x*(2 - 9*x - 4*x^2)/((1 - 5*x + x^2)*(1 - 5*x - x^2)).
a(n) = (1/2)*((A052918(n) - 2*A052918(n-1)) - (A004254(n+1) - 6*A004254(n))). - G. C. Greubel, Sep 11 2021
MATHEMATICA
M = {{0, 0, 0, 1}, {1, 5, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 5}}; v[1]= {0, 1, 1, 2}; v[n_]:= v[n]= M.v[n-1]; Table[v[n][[1]], {n, 20}]
LinearRecurrence[{10, -25, 0, 1}, {0, 2, 11, 56}, 30] (* Harvey P. Dale, Nov 29 2018 *)
PROG
(Magma) I:=[0, 2, 11, 56]; [n le 4 select I[n] else 10*Self(n-1) - 25*Self(n-2) + Self(n-4): n in [1..31]]; // G. C. Greubel, Sep 11 2021
(Sage)
def A106804_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( x*(2-9*x-4*x^2)/((1-5*x+x^2)*(1-5*x-x^2)) ).list()
A106804_list(30) # G. C. Greubel, Sep 11 2021
CROSSREFS
Sequence in context: A212388 A198769 A037554 * A361219 A213098 A041129
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, May 30 2005
EXTENSIONS
Edited by the Associate Editors of the OEIS, Apr 09 2009
Mathematica code fixed by Olivier Gérard, Dec 13 2011
STATUS
approved

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Last modified April 15 11:55 EDT 2024. Contains 371681 sequences. (Running on oeis4.)