%I A005227 M1029
%S A005227 0,1,1,2,4,6,19,20,111,116,567,641,4718
%N A005227 Number of atomic species of degree n which are not nontrivial substitutions.
%D A005227 J. Labelle and Y. N. Yeh, The relation between Burnside rings and combinatorial 
               species, J. Combin. Theory, A 50 (1989), 269-284.
%D A005227 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%F A005227 Define b(n), c(n): b(1)=c(0)=0. b(k)=a(k), k>1. c(k)=A000638(k), k>0. 
               A005226(n) is Dirichlet convolution of b and c. - Christian G. Bower 
               (bowerc(AT)usa.net), Feb 23 2006
%Y A005227 Cf. A005226.
%Y A005227 Sequence in context: A066894 A111115 A143085 this_sequence A108439 A152482 
               A045960
%Y A005227 Adjacent sequences: A005224 A005225 A005226 this_sequence A005228 A005229 
               A005230
%K A005227 nonn,hard
%O A005227 0,4
%A A005227 N. J. A. Sloane (njas(AT)research.att.com).
%E A005227 a(8), a(11) corrected and a(12) added by Christian G. Bower (bowerc(AT)usa.net), 
               Feb 23 2006 based on Goetz Pfeiffer's edit to A000638.