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%I A005227 M1029 #37 Oct 27 2023 06:02:29
%S A005227 0,1,1,2,4,6,19,20,111,116,567,641,4718,4772,35489,46012,389277,
%T A005227 487408,4616580
%N A005227 Number of atomic species of degree n which are not nontrivial substitutions.
%D A005227 Labelle, Jacques. Quelques espèces sur les ensembles de petite cardinalité, Ann. Sc. Math. Québec 9.1 (1985): 31-58.
%D A005227 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A005227 H. Decoste, G. Labelle, & J. Labelle, <a href="/A005226/a005226.pdf">Espèces sur les petites cardinalités Tableaux divers</a>, Université du Québec à Montréal (octobre 1988), Unpublished.
%H A005227 Jacques Labelle, <a href="/A005226/a005226_1.pdf">Quelques espèces sur les ensembles de petite cardinalité</a>, Ann. Sc. Math. Québec 9.1 (1985): 31-58. (Annotated scanned copy of preprint)
%H A005227 J. Labelle and Y. N. Yeh, <a href="http://dx.doi.org/10.1016/0097-3165(89)90019-8">The relation between Burnside rings and combinatorial species</a>, J. Combin. Theory, A 50 (1989), 269-284.
%F A005227 Define b(n), c(n), d(n): b(1)=d(1)=0. b(k)=a(k), k>1. c(k)=A000638(k), k>0, d(k)=A005226(k), k>1. d is Dirichlet convolution of b and c. - _Christian G. Bower_, Feb 23 2006
%Y A005227 Cf. A005226.
%K A005227 nonn,hard,more
%O A005227 0,4
%A A005227 _N. J. A. Sloane_
%E A005227 a(8), a(11) corrected and a(12) added by _Christian G. Bower_, Feb 23 2006 based on Goetz Pfeiffer's edit to A000638
%E A005227 a(13)-a(18) from _Vaclav Kotesovec_, Jul 18 2022

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