OFFSET
1,1
LINKS
Jean-Christophe Novelli and Jean-Yves Thibon, Free quasi-symmetric functions and descent algebras for wreath products, and noncommutative multi-symmetric functions (2008); arXiv:0806.3682 [math.CO], 2008; Discrete Math. 310 (2010), no. 24, 3584-3606. See Eq. 35.
MATHEMATICA
terms = 18; f[t_] = 1 + Sum[n! t^n, {n, 1, terms+1}];
A122827 = CoefficientList[(f[t] - 1)/f[t]^2 + O[t]^(terms+1), t] // Rest;
2^Range[terms]*A122827 (* Jean-François Alcover, Feb 13 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 23 2012
STATUS
approved