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 A009591 Expansion of e.g.f. sinh(sin(x)) * sin(x) (even powers only). 2
 0, 2, -4, -42, 888, -8086, -115468, 8863806, -275344656, 2488177106, 369676840940, -34139482063962, 1691837365047912, -16526563632072646, -7669129653528552220, 1088114395890103645710, -87525176659638470236704 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS G. C. Greubel, Table of n, a(n) for n = 0..250 FORMULA a(n) = 2*Sum_{j=1..n} 4^(n-j)/(2*j-1)!*Sum_{i=0..j-1} (i-j)^(2*n)* binomial(2*j,i)*(-1)^(n+j-i). - Vladimir Kruchinin, Jun 09 2011 MATHEMATICA With[{nn=40}, Take[CoefficientList[Series[Sinh[Sin[x]]Sin[x], {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Dec 08 2012 *) PROG (Maxima) a(n):=2*sum(4^(n-j)/(2*j-1)!*sum((i-j)^(2*n)*binomial(2*j, i)*(-1)^(n+j-i), i, 0, j-1), j, 1, n); /* Vladimir Kruchinin, Jun 09 2011 */ (PARI) x='x+O('x^40); v=Vec(serlaplace(sinh(sin(x))*sin(x))); concat([0], vector(#v\2 , n, v[2*n-1])) \\ G. C. Greubel, Jan 30 2018 CROSSREFS Sequence in context: A215921 A009811 A364237 * A009717 A018317 A359876 Adjacent sequences: A009588 A009589 A009590 * A009592 A009593 A009594 KEYWORD sign AUTHOR R. H. Hardin EXTENSIONS Extended with signs by Olivier Gérard, Mar 15 1997 STATUS approved

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Last modified August 13 00:55 EDT 2024. Contains 375113 sequences. (Running on oeis4.)