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 A133004 #15 Jan 24 2024 12:18:47
%S A133004 0,1,-2,5,-68,193,-655,19349,-57736,520343,-43184789,366043159,
%T A133004 -36085302154,219183008719,-333043820161,1124780733391,
%U A133004 -2033896175720464,6178608669563333,-106918567902798017,178383998798531120359,-54061775649488096702,2291400664110090118501,-56920102349900658177643
%N A133004 Numerators of Blandin-Diaz compositional Bernoulli numbers C_2,n.
%H A133004 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. 14, first table.
%e A133004 0, 1, -23, 56, -68/45, 193/54, -655/63, 19349/540, -57736/405, 520343/810.
%o A133004 (PARI) my(x='x+O('x^30)); apply(numerator, concat(0, Vec(serlaplace(serreverse(2*(exp(x)-1-x)/x))))) \\ _Michel Marcus_, Jan 24 2024
%Y A133004 Denominators are A133005.
%Y A133004 Cf. A132092-A132099.
%K A133004 frac,sign
%O A133004 0,3
%A A133004 _Jonathan Vos Post_, Aug 09 2007
%E A133004 More terms from _Michel Marcus_, Jan 24 2024