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Search: id:A005227
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| A005227 |
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Number of atomic species of degree n which are not nontrivial substitutions.
(Formerly M1029)
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+0
3
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| 0, 1, 1, 2, 4, 6, 19, 20, 111, 116, 567, 641, 4718
(list; graph; listen)
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OFFSET
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0,4
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REFERENCES
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J. Labelle and Y. N. Yeh, The relation between Burnside rings and combinatorial species, J. Combin. Theory, A 50 (1989), 269-284.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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FORMULA
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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
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CROSSREFS
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Cf. A005226.
Sequence in context: A066894 A111115 A143085 this_sequence A108439 A152482 A045960
Adjacent sequences: A005224 A005225 A005226 this_sequence A005228 A005229 A005230
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KEYWORD
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nonn,hard
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
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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.
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