login
This site is supported by donations to The OEIS Foundation.

 

Logo

The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A005227 Number of atomic species of degree n which are not nontrivial substitutions.
(Formerly M1029)
2
0, 1, 1, 2, 4, 6, 19, 20, 111, 116, 567, 641, 4718 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

REFERENCES

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

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).

LINKS

Table of n, a(n) for n=0..12.

FORMULA

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

CROSSREFS

Cf. A005226.

Sequence in context: A111115 A195328 A143085 * A185185 A234019 A279188

Adjacent sequences:  A005224 A005225 A005226 * A005228 A005229 A005230

KEYWORD

nonn,hard,more

AUTHOR

N. J. A. Sloane.

EXTENSIONS

a(8), a(11) corrected and a(12) added by Christian G. Bower, Feb 23 2006 based on Goetz Pfeiffer's edit to A000638.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 28 02:53 EDT 2017. Contains 287211 sequences.