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 A383995 #14 May 28 2025 16:38:06
%S A383995 0,1,-11,61,-215,-1559,62941,-1371131,26310481,-474554735,7824076741,
%T A383995 -98881279859,-176260664711,87457412423161,-5077434546358355,
%U A383995 234510433823788501,-10016559114085864799,413333665704129673249,-16704968283664639137899,660340818239784197391325
%N A383995 Series expansion of the exponential generating function exp(ff6^!(x)) - 1 where ff6^!(x) = x * (1-3*x-x^2+x^3) / (1+3*x+x^2-x^3).
%C A383995 The series ff6^!(x) is the inverse for the substitution of the series ff6(x) (given by A231690), given by the suspension of the Koszul dual of FF6. - _Bérénice Delcroix-Oger_, May 28 2025
%H A383995 Michael De Vlieger, <a href="/A383995/b383995.txt">Table of n, a(n) for n = 0..393</a>
%H A383995 Bérénice Delcroix-Oger and Clément Dupont, <a href="https://arxiv.org/abs/2505.06094">Lie-operads and operadic modules from poset cohomology</a>, arXiv:2505.06094 [math.CO], 2025. See p. 32, Table 3, operad "FF6".
%t A383995 nn = 19; f[x_] := Exp[x] - 1;
%t A383995 Range[0, nn]! * CoefficientList[Series[f[x*(1 - 3*x - x^2 + x^3)/(1 + 3*x + x^2 - x^3)], {x, 0, nn}], x]
%Y A383995 Cf. A003725, A097388, A111884, A112242, A177885, A318215, A383989, A383990, A383991, A383992, A383993, A383994.
%K A383995 sign
%O A383995 0,3
%A A383995 _Michael De Vlieger_, May 16 2025