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 A060055 #43 Aug 02 2023 10:44:04
%S A060055 2,12,720,30240,1209600,47900160,1307674368000,74724249600,
%T A060055 10670622842880000,5109094217170944000,802857662698291200000,
%U A060055 14101100039391805440000,1693824136731743669452800000
%N A060055 Denominators of nonzero numbers appearing in the Euler-Maclaurin summation formula. (See A060054 for the definition of these numbers.)
%C A060055 Denominators of nonzero coefficients in the series expansion around zero of cot(x/2)/2, disregarding the first term. - _Fredrik Johansson_, Aug 20 2006
%D A060055 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 16 (3.6.28), p. 806 (23.1.30), p. 886 (25.4.7).
%H A060055 Vincenzo Librandi, <a href="/A060055/b060055.txt">Table of n, a(n) for n = 1..200</a>
%H A060055 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
%H A060055 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 16 (3.6.28), p. 806 (23.1.30), p. 886 (25.4.7).
%H A060055 Zhanna Kuznetsova, and Francesco Toppan, <a href="https://arxiv.org/abs/2103.04385">Classification of minimal Z_2 X Z_2-graded Lie (super)algebras and some applications</a>, arXiv:2103.04385 [math-ph], 2021.
%t A060055 Join[{2}, f[n_]:=Denominator[-(-1)^n BernoulliB[2 n]/(2 n)!]; Table[f[n], {n, 30}]] (* _Robert G. Wilson v_, Sep 02 2004 *) (* adapted by _Vincenzo Librandi_, May 04 2017 *)
%t A060055 Join[{2}, Denominator[Table[SeriesCoefficient[x^2/(1 - E^x), {x, 0, n}], {n, 3, 25, 2}]]] (* _Terry D. Grant_, Jun 01 2017 *)
%o A060055 (Magma) [2] cat [Denominator(-(-1)^n*Bernoulli(2*n)/Factorial(2*n)): n in [1..15]]; // _Vincenzo Librandi_, Jun 04 2017
%Y A060055 Numerators give A060054.
%K A060055 nonn,frac,easy
%O A060055 1,1
%A A060055 _Wolfdieter Lang_, Feb 16 2001