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A127896
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Expansion of 1/(1+2x+3x^2+x^3).
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2
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1, -2, 1, 3, -7, 4, 10, -25, 16, 33, -89, 63, 108, -316, 245, 350, -1119, 943, 1121, -3952, 3598, 3539, -13920, 13625, 10971, -48897, 51256, 33208, -171287, 191694, 97265, -598325, 713161, 271388, -2083934
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Row sums of A127895. Series reversion is A127897.
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FORMULA
| a(n) = sum(k=0..n, (-1)^(n-k)*C(n+2k+2,n-k)).
a(n) = -2*a(n-1) -3*a(n-2) -a(n-3), n>=3. - Vincenzo Librandi, Mar 22 2011
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MATHEMATICA
| CoefficientList[Series[1/(1+2x+3x^2+x^3), {x, 0, 40}], x] (* From Harvey P. Dale, Apr 19 2011 *)
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CROSSREFS
| Sequence in context: A073901 A176120 A058170 * A010757 A019320 A201615
Adjacent sequences: A127893 A127894 A127895 * A127897 A127898 A127899
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KEYWORD
| easy,sign
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Feb 04 2007
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