%I #10 Nov 22 2014 10:15:08
%S 1,-12,-5152,-7351872,23844355328,2971598628507648,
%T 259172055916070309888,31874732857037574011240448,
%U 5625494806370311291378460131328,1331819025115560536529968068424368128,357000031318983624394235069073760267010048,30988128279193785865476747562711031784709029888
%N cos(sec(x)-sech(x))=1-12/4!*x^4-5152/8!*x^8-7351872/12!*x^12...
%t With[{nn=50},Take[CoefficientList[Series[Cos[Sec[x]-Sech[x]],{x,0,nn}],x] Range[0,nn-2]!,{1,-1,4}]] (* _Harvey P. Dale_, Nov 22 2014 *)
%K sign
%O 0,2
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E More terms from _N. J. A. Sloane_, Dec 17 2011
|