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A272642
Expansion of (x^4+x^3+x^2-x-1)/(x^4+2*x^3+2*x^2+x-1).
2
1, 2, 3, 8, 18, 42, 97, 225, 521, 1207, 2796, 6477, 15004, 34757, 80515, 186514, 432062, 1000877, 2318544, 5370936, 12441840, 28821677, 66765773, 154663743, 358280483, 829961192, 1922615417, 4453762510, 10317196211, 23899913257, 55364446116, 128252427562, 297098342519, 688232003132
OFFSET
0,2
REFERENCES
Based on a suggestion of Wolfdieter Lang in A272362.
FORMULA
G.f.: (x^4+x^3+x^2-x-1)/(x^4+2*x^3+2*x^2+x-1).
a(n) = 2*a(n-1) + a(n-2) - a(n-4) - a(n-5). - Vincenzo Librandi, May 08 2016
MATHEMATICA
CoefficientList[Series[(x^4 + x^3 + x^2 - x - 1)/(x^4 + 2 x^3 + 2 x^2 + x - 1), {x, 0, 40}], x] (* Vincenzo Librandi, May 08 2016 *)
PROG
(Magma) m:=40; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!((x^4+x^3+x^2-x-1)/(x^4+2*x^3+2*x^2+x-1))); // Bruno Berselli, May 08 2016
CROSSREFS
A272362 gives partial sums.
Sequence in context: A129955 A034066 A034076 * A241906 A079224 A002369
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 07 2016
STATUS
approved