A013473 - OEIS

%I #7 Apr 08 2016 12:23:02

%S -2,238,-715682,12212600398,-693692750003522,99086243037690160558,

%T -29914788669101073817179362,16957033980662331163451765544718,

%U -16560275867709925788740349268459459202,26102948307736145181548875145546574191456878

%N arctan(cos(x)-cosh(x))=238/6!*x^6-715682/10!*x^10+12212600398/14!*x^14...

%t With[{nn=40},Take[CoefficientList[Series[ArcTan[Cos[x]-Cosh[x]],{x,0,nn}],x] Range[0,nn-2]!,{3,-1,4}]] (* _Harvey P. Dale_, Apr 08 2016 *)

%K sign

%O 0,1

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

%E Corrected and extended by _Harvey P. Dale_, Apr 08 2016