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%I #16 Dec 22 2025 10:40:11
%S 0,1,4,4,-480,-12208,87488,27536192,1208587264,-78798149376,
%T -18257785424896,-819996200344576,272839221776048128,
%U 64613626344768458752,380326723619536551936,-3364767702453136892805120
%N Expansion of tan(sin(x))*sinh(x)/2.
%H Jose Torres-Jimenez, Roberto Blanco-Rocha, and Carlos Lara-Alvarez, <a href="https://doi.org/10.1109/ACCESS.2025.3625854">LU Decomposition of delta-Vandermonde Matrices</a>, IEEE Access 13 (2025) 187361-187372. See references.
%t With[{nn=30},Take[CoefficientList[Series[Tan[Sin[x]]*Sinh[x]/2,{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, Mar 01 2025 *)
%Y Cf. A009666.
%K sign
%O 0,3
%A _R. H. Hardin_
%E Extended with signs Mar 1997
%E Previous Mathematica program replaced by _Harvey P. Dale_, Mar 01 2025