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 A133003 #32 Sep 01 2021 11:44:25
%S A133003 1,4,72,48,21600,540,2540160,483840,36288000,896000,31614105600,
%T A133003 1149603840,7139902049280000,2196892938240000,941525544960000,
%U A133003 15216574464000,16326052949606400000,443241256550400000,11991344662654156800000,1100420292929126400000
%N A133003 Denominators of Blandin-Diaz compositional Bernoulli numbers (B^S)_1,n.
%C A133003 Numerators are A133002.
%H A133003 Daniel Suteu, <a href="/A133003/b133003.txt">Table of n, a(n) for n = 0..200</a>
%H A133003 Hector Blandin and Rafael Diaz, <a href="https://arxiv.org/abs/0708.0809">Compositional Bernoulli numbers</a>, arXiv:0708.0809 [math.CO], 2007-2008, p. 11, 1st table.
%F A133003 a(n) = denominator(f(n) * n!), where f(0) = 1, f(n) = -Sum_{k=0..n-1} f(k) / ((n-k+1)!)^2. - _Daniel Suteu_, Feb 23 2018
%F A133003 E.g.f. for fractions: x / (BesselI(0,2*sqrt(x)) - 1). - _Ilya Gutkovskiy_, Sep 01 2021
%e A133003 1, -1/4, 5/72, -1/48, 139/21600, -1/540, 859/2540160, 71/483840, -9769/36288000 (corrected by _Daniel Suteu_, Feb 24 2018).
%t A133003 f[0] = 1; f[n_] := f[n] = -Sum[f[k]/((n - k + 1)!)^2, {k, 0, n - 1}]; a[n_] := Denominator[f[n]*n!]; Table[a[n], {n, 0, 19}] (* _Jean-François Alcover_, Feb 25 2018, after _Daniel Suteu_ *)
%Y A133003 Cf. A132092, A132093, A132094, A132095, A132096, A132097, A132098, A132099.
%Y A133003 Cf. A133000, A133001, A133002, A133004, A133005.
%K A133003 nonn,frac
%O A133003 0,2
%A A133003 _Jonathan Vos Post_, Aug 09 2007
%E A133003 Terms beyond a(8) from _Daniel Suteu_, Feb 24 2018