%I #11 Jun 17 2021 19:57:47
%S 2,-7,273,-25953,4935993,-1550066093,727992520877,-477706621753073,
%T 417426531017836113,-468554517235713007893,657016357969010026027221,
%U -1125485924474211875062297145,2312766814097571417683969638841
%N arcsinh(arcsinh(x)+tan(x))=2*x-7/3!*x^3+273/5!*x^5-25953/7!*x^7...
%H Vaclav Kotesovec, <a href="/A013097/b013097.txt">Table of n, a(n) for n = 0..200</a>
%F Limit n->infinity (a(n)/((-1)^n*(2*n+1)!*n^(-3/2)))^(1/(2*n+1)) = 1.97099530685431257534... - _Vaclav Kotesovec_, Nov 01 2013
%t Table[n!*SeriesCoefficient[ArcSinh[ArcSinh[x]+Tan[x]],{x,0,n}],{n,1,41,2}] (* _Vaclav Kotesovec_, Nov 01 2013 *)
%t With[{nn=30},Take[CoefficientList[Series[ArcSinh[ArcSinh[x]+Tan[x]],{x,0,nn}],x] Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Jun 17 2021 *)
%K sign
%O 0,1
%A Patrick Demichel (patrick.demichel(AT)hp.com)
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