%I #11 Feb 04 2015 05:00:08

%S 0,-2,0,-2,2240,-2,137280,-403603202,10325120,-223480857602,

%T 1042911543845760,-119078050291202,2638564062897339200,

%U -16807721436490038912002,5561493227350293205440

%N arcsinh(sin(x)-sinh(x))=-2/3!*x^3-2/7!*x^7+2240/9!*x^9-2/11!*x^11...

%H Vaclav Kotesovec, <a href="/A013374/b013374.txt">Table of n, a(n) for n = 0..238</a>

%t With[{nn=40}, Flatten[{0,Take[Drop[CoefficientList[Series[ArcSinh[Sin[x]-Sinh[x]], {x,0,nn}],x]Range[0,nn-1]!,2],{2,-1,2}]}]] (* _Harvey P. Dale_, Oct 19 2011 *)

%K sign

%O 0,2

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

%E Prepended missing a(0)=0 from _Vaclav Kotesovec_, Feb 04 2015