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 A136558 G.f.: A(x) = Sum_{n>=0} arcsinh( 2^(2n+1)*x )^(2n+1) / (2n+1)!; a power series in x with integer coefficients. 4
 2, 0, 84, 0, 276892, 0, 111457917800, 0, 6660816097416169260, 0, 66597307693046550483175282456, 0, 120167520447600665027319450022840022638104, 0, 41233407800231936275686869695450406221641586822849599440, 0, 2796405930832642696090353299413183601303402593622351242536692586333202380, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS G. C. Greubel, Table of n, a(n) for n = 1..49 EXAMPLE G.f.: A(x) = 2*x + 84*x^3 + 276892*x^5 + 111457917800*x^7 + ... MATHEMATICA Rest@With[{m=30}, CoefficientList[Series[Sum[ArcSinh[2^(2*j+1)*x]^(2*j+1)/(2*j+1)!, {j, 0, m+2}], {x, 0, m}], x]] (* G. C. Greubel, Mar 15 2021 *) PROG (PARI) {a(n)=polcoeff(sum(k=0, n\2, asinh(2^(2*k+1)*x +x*O(x^n))^(2*k+1)/(2*k+1)!), n)} (Magma) m:=30; R:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( (&+[Argsinh(2^(2*j+1)*x)^(2*j+1)/Factorial(2*j+1): j in [0..m+2]]) )); // G. C. Greubel, Mar 15 2021 CROSSREFS Cf. A136559. Sequence in context: A012334 A012451 A012447 * A156490 A216678 A136559 Adjacent sequences: A136555 A136556 A136557 * A136559 A136560 A136561 KEYWORD nonn AUTHOR Paul D. Hanna, Jan 10 2008 STATUS approved

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Last modified June 4 03:55 EDT 2023. Contains 363118 sequences. (Running on oeis4.)