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A138034 Expansion of (1+3*x^2)/(1-x+x^2). 11
1, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3, 2, -1, -3, -2, 1, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
Essentially a duplicate of A119910: 1, followed by A119910. - Joerg Arndt, Nov 14 2014
LINKS
Karem Boubaker and Lin Zhang, Fermat-linked relations for the Boubaker polynomial sequences via Riordan matrices analysis, arXiv preprint arXiv:1203.2082, 2012. - From N. J. A. Sloane, Sep 15 2012
FORMULA
a(n) = A119910(n), n>=1.
G.f.: (1+3*x^2)/(1-x+x^2). a(n)=a(n-1)-a(n-2), n>2.
MATHEMATICA
CoefficientList[Series[(1 + 3*x^2)/(1 - x + x^2), {x, 0, 100}], x] (* Wesley Ivan Hurt, Jan 15 2017 *)
LinearRecurrence[{1, -1}, {1, 1, 3}, 120] (* Harvey P. Dale, Jun 14 2024 *)
CROSSREFS
Sequence in context: A280048 A119910 A130784 * A229216 A087818 A112746
KEYWORD
sign,easy,changed
AUTHOR
Karem Boubaker (mmbb11112000(AT)yahoo.fr), Mar 01 2008; corrected Mar 03 2008
STATUS
approved

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Last modified June 15 08:58 EDT 2024. Contains 373402 sequences. (Running on oeis4.)