This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A046989 #43 Jan 02 2025 12:15:59
%S A046989 1,6,180,2835,37800,467775,3831077250,127702575,2605132530000,
%T A046989 350813659321125,15313294652906250,147926426347074375,
%U A046989 2423034863565078262500,144228265688397515625,3952575621190533915703125,84913182070036240111050234375,999843529136357459316262500000
%N A046989 Denominators of Taylor series expansion in powers of x^2 of log(x/sin x).
%C A046989 For the numerators see A283301.
%D A046989 L. V. Ahlfors, Complex Analysis, McGraw-Hill, 1979, p. 205
%D A046989 T. J. I'a. Bromwich, Introduction to the Theory of Infinite Series, Macmillan, 2nd. ed. 1949, p. 222, series for log(H(x)/x).
%D A046989 L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 88.
%D A046989 CRC Standard Mathematical Tables and Formulae, 30th ed. 1996, p. 42.
%D A046989 Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 32, equation 32:6:4 at page 301.
%F A046989 log(x/sin(x)) = Sum_{n>0} (2^(2*n-1)*(-1)^(n+1)*B(2*n)/(n*(2*n)!) * x^(2*n)). - _Ralf Stephan_, Apr 01 2015 [corrected by _Roland J. Etienne_, Apr 19 2016]
%e A046989 log(x/sin(x)) = 1/6*x^2 + 1/180*x^4 + 1/2835*x^6 + 1/37800*x^8 + 1/467775*x^10 + 691/3831077250*x^12 + ...
%t A046989 Join[{1},Denominator[Take[CoefficientList[Series[Log[x/Sin[x]],{x,0,50}], x],{3,-1,2}]]] (* _Harvey P. Dale_, Apr 27 2012 *)
%o A046989 (Sage)
%o A046989 def a(n): return -numerator((n*factorial(2*n))/(2^(2*n-1)*(-1)^n*bernoulli(2*n))) # _Ralf Stephan_, Apr 01 2015
%Y A046989 Cf. A283301 (numerators), A027641/A027642 (Bernoulli).
%K A046989 nonn,easy,frac,nice
%O A046989 0,2
%A A046989 _N. J. A. Sloane_