A005227 - OEIS

%I M1029 #37 Oct 27 2023 06:02:29

%S 0,1,1,2,4,6,19,20,111,116,567,641,4718,4772,35489,46012,389277,

%T 487408,4616580

%N Number of atomic species of degree n which are not nontrivial substitutions.

%D Labelle, Jacques. Quelques espèces sur les ensembles de petite cardinalité, Ann. Sc. Math. Québec 9.1 (1985): 31-58.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H 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, Université du Québec à Montréal (octobre 1988), Unpublished.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 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 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 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 Cf. A005226.

%K nonn,hard,more

%O 0,4

%A _N. J. A. Sloane_

%E 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 a(13)-a(18) from _Vaclav Kotesovec_, Jul 18 2022