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A011780 Expansion of 1/(1-2*x)^3/(1-x^2)^2. 1
1, 6, 26, 92, 291, 850, 2348, 6216, 15925, 39742, 97086, 233012, 550983, 1286442, 2970960, 6796320, 15417945, 34719510, 77672290, 172743180, 382147691, 841346306, 1844250996, 4026531832, 8758949501, 18989322990 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

FORMULA

a(n) = (n^2 +n/3 +10/3)*2^(n+3)/9 +(n/4 +1)*(-1)^n/27 -n/4 -2. [Bruno Berselli, Jun 24 2013]

MATHEMATICA

CoefficientList[Series[1 / (1 - 2 x)^3 / (1 - x^2)^2, {x, 0, 40}], x] (* Vincenzo Librandi, Jun 23 2013 *)

PROG

(MAGMA) m:=30; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-2*x)^3/(1-x^2)^2)); // Vincenzo Librandi, Jun 24 2013

CROSSREFS

Sequence in context: A166214 A032169 A032196 * A036631 A224288 A036638

Adjacent sequences:  A011777 A011778 A011779 * A011781 A011782 A011783

KEYWORD

nonn,easy

AUTHOR

Emeric Deutsch

STATUS

approved

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Last modified July 19 09:33 EDT 2019. Contains 325155 sequences. (Running on oeis4.)