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 A261056 Expansion of  ( 2-x^2 ) / (x^2+2*x-1)^2 . 1
 2, 8, 27, 84, 248, 708, 1973, 5400, 14574, 38896, 102863, 269964, 703972, 1825612, 4711785, 12110064, 31010266, 79148184, 201420163, 511233156, 1294489296, 3270662036, 8247316765, 20758752648, 52163239622, 130875524096, 327893289783, 820410399804, 2050189683644 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS 2nd column of A210637. LINKS Index entries for linear recurrences with constant coefficients, signature (4,-2,-4,-1) FORMULA a(n) = 2*A006645(n+2) -A006645(n). MATHEMATICA CoefficientList[Series[(2-x^2)/(x^2+2*x-1)^2, {x, 0, 40}], x] (* or *) LinearRecurrence[{4, -2, -4, -1}, {2, 8, 27, 84}, 40] (* Harvey P. Dale, Feb 24 2017 *) CROSSREFS Cf. A210637. Sequence in context: A100505 A102759 A292698 * A295135 A076884 A138388 Adjacent sequences:  A261053 A261054 A261055 * A261057 A261058 A261059 KEYWORD nonn,easy AUTHOR R. J. Mathar, Aug 08 2015 STATUS approved

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Last modified November 27 01:16 EST 2021. Contains 349344 sequences. (Running on oeis4.)