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Expansion of e.g.f.: sech(sin(x)*exp(x)).
1

%I #15 Sep 08 2022 08:44:38

%S 1,0,-1,-6,-15,60,1023,6062,-9247,-652680,-7332289,-13792350,

%T 994947921,19248140340,119312444223,-2747842718122,-91993600741951,

%U -1070543140984080,10423240065585023,710021632610736714

%N Expansion of e.g.f.: sech(sin(x)*exp(x)).

%H G. C. Greubel, <a href="/A012294/b012294.txt">Table of n, a(n) for n = 0..440</a> (terms 0..200 from Vincenzo Librandi)

%e E.g.f. = 1 - x^2/2! - 6*x^3/3! - 15*x^4/4! + 60*x^5/5! + ...

%t With[{nn=20},CoefficientList[Series[Sech[Sin[x]Exp[x]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Jun 04 2012 *)

%o (PARI) x='x+O('x^30); Vec(serlaplace(1/cosh(sin(x)*exp(x)))) \\ _G. C. Greubel_, Oct 26 2018

%o (Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!( 1/Cosh(Sin(x)*Exp(x)) )); [Factorial(n-1)*b[n]: n in [1..m-1]]; // _G. C. Greubel_, Oct 26 2018

%K sign

%O 0,4

%A Patrick Demichel (patrick.demichel(AT)hp.com)

%E Definition clarified by _Harvey P. Dale_, Jun 04 2012