%I #13 Oct 17 2017 14:35:43
%S 1,4,31,329,4316,66543,1172077,23139068,504673027,12023659317,
%T 310112290044,8596075462411,254551364575929,8012189624924740,
%U 266901629110149847,9374566215360038977,346044223246303101068
%N E.g.f. exp(sum_{d|M} (exp(d*x)-1)/d), M=8.
%H Vincenzo Librandi, <a href="/A141005/b141005.txt">Table of n, a(n) for n = 0..200</a>
%t 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, 8], {n, 0, 30}] (* _Vincenzo Librandi_, Dec 12 2012 *)
%Y Column k=8 of A162663.
%K nonn
%O 0,2
%A _R. J. Mathar_, Jul 11 2008