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 A383988 #31 May 28 2025 09:19:43
%S A383988 0,1,-2,12,-110,1380,-22022,426972,-9747950,256176660,-7617417302,
%T A383988 252851339532,-9268406209790,371843710214340,-16206868062692582,
%U A383988 762569209601624892,-38525315595630383630,2079964082064837282420,-119513562475103977951862
%N A383988 Series expansion of the exponential generating function -postLie(1-exp(x)) where postLie(x) = -log((1 + sqrt(1-4*x)) / 2) (given by A006963).
%C A383988 The series -postLie(-x) is the inverse for the substitution of the series comTrias(x), given by the suspension of the Koszul dual of comTrias. - _Bérénice Delcroix-Oger_, May 28 2025
%H A383988 Michael De Vlieger, <a href="/A383988/b383988.txt">Table of n, a(n) for n = 0..374</a>
%H A383988 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. 28, Table 2, commutative triassociative operad "ComTrias".
%t A383988 nn = 18; f[x_] := Log[(1 + Sqrt[1 + 4*x])/2];
%t A383988 Range[0, nn]! * CoefficientList[Series[f[-(1 - Exp[x])], {x, 0, nn}], x]
%Y A383988 Cf. A002050, A006531, A084099, A097388, A101851, A114285, A225883, A383985, A383986, A383987, A383989. Composition of -A006963(-x) and exp(x)-1.
%K A383988 sign,easy
%O A383988 0,3
%A A383988 _Michael De Vlieger_, May 16 2025