A008961 - OEIS

%I #12 Jul 21 2018 16:02:38

%S 1,-1,-23,-947,-1733,-21781,-43311113,-2723179,-6414155401,

%T -785453333257,-7699945982293,-66166822052531,-239092621861482143,

%U -271166505959717,-74473963890443961601,-163219188105035970948619,-153312677184465775645847,-625566886054776334597601

%N Numerators of Taylor series for 1/(sin x + tan x).

%H G. C. Greubel, <a href="/A008961/b008961.txt">Table of n, a(n) for n = 0..269</a>

%t Take[Numerator[CoefficientList[2x #&/@Normal[Series[1/(Sin[x]+Tan[x]),{x,0,40}]],x]],{1,-1,2}] (* _Harvey P. Dale_, Feb 11 2015 *)

%Y Cf. A009724.

%K sign,frac

%O 0,3

%A _N. J. A. Sloane_

%E More terms from _Harvey P. Dale_, Feb 11 2015