A185159 a(n) = 2^n*A122827(n).

2, 0, 8, 96, 1248, 18176, 295040, 5294592, 104269312, 2239225856, 52150118400, 1310675066880, 35390943453184, 1022570290544640, 31498715705147392, 1030904079324413952, 35736902010299351040, 1308417934560279396352

Offset: 1

Author

N. J. A. Sloane, Jan 23 2012

Keywords

• nonn

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.

Crossrefs

Cf. A122827.

Programs

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 *)