A012867 - OEIS

%I #15 Aug 31 2018 03:36:26

%S 0,-2,1,-313,317,-7813,6895597,-61916737,10655226077,-41786390722733,

%T 613552118040217,-41640337444573141,6761598195684420293,

%U -140000933764069408573,81775784693678733811,-368555295637618487393608489,41000094641259185671029500461,-243445658683280857337557514581

%N Numerators of coefficients in Taylor series expansion of log(cotan(x)*arctan(x)).

%H Vincenzo Librandi, <a href="/A012867/b012867.txt">Table of n, a(n) for n = 0..250</a>

%e -(2/3)*x^2 + (1/15)*x^4 - (313/2835)*x^6 + (317/5670)*x^8 - (7813/155925)*x^10 + ...

%t Numerator[Take[CoefficientList[Series[Log[Cot[x]ArcTan[x]],{x,0,40}], x],{1,-1,2}]] (* _Harvey P. Dale_, May 18 2012 *)

%Y Cf. A202621.

%K sign,frac

%O 0,2

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

%E Corrected by _N. J. A. Sloane_, Dec 21 2011