A141004 Expansion of e.g.f. exp(Sum_{d|6} (exp(d*x)-1)/d).

1, 4, 28, 258, 2892, 37778, 560124, 9256010, 168182044, 3325057826, 70934634236, 1621828212826, 39517131361884, 1021237022557682, 27877344103738940, 800976143703407210, 24148078430008534428, 761815206361252780098, 25087729474993723079548

Offset: 0

Author

R. J. Mathar, Jul 11 2008

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200

Crossrefs

u[n,j] generates for j=1, A000110 Bell numbers; j=2, A002872 "Sorting numbers"; j=3, A002874 "Sorting numbers"; j=4, A141003 (Mathar); j=5, A036075 "Sorting numbers"; j=6, A141004 (Mathar); j=7, A036077 "Sorting numbers". - Wouter Meeussen, Dec 06 2008

Column k=6 of A162663.

Programs

Mathematica

u[0,j_]:=1;u[k_,j_]:=u[k,j]=Sum[Binomial[k-1,i-1]Plus@@(u[k-i,j]#^(i-1)&/@Divisors[j]),{i,k}]; Table[u[n,6],{n,0,18}] (* Wouter Meeussen, Dec 06 2008 *)