cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-9 of 9 results.

A094927 Number of nonisomorphic (possibly decomposable) self-dual quantum codes on n qubits.

Original entry on oeis.org

1, 2, 3, 6, 11, 26, 59, 182, 675, 3990, 45144, 1323363
Offset: 1

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Author

Lars Eirik Danielsen (larsed(AT)ii.uib.no) and Matthew G. Parker (matthew(AT)ii.uib.no), Jun 17 2004

Keywords

Comments

Also number of nonisomorphic (indecomposable or decomposable) self-dual codes of Type 4^H+ and length n.

References

  • L. E. Danielsen and M. G. Parker, On the classification of all self-dual additive codes over GF(4) of length up to 12, Preprint 2005.

Crossrefs

See A090899 for more information. Cf. also A110302, A110306.

A110302 Number of inequivalent indecomposable self-dual codes of Type {4^H+}_II and length 2n.

Original entry on oeis.org

1, 1, 1, 4, 14, 103, 2926
Offset: 0

Views

Author

N. J. A. Sloane, Sep 09 2005

Keywords

References

  • L. E. Danielsen and M. G. Parker, On the classification of all self-dual additive codes over GF(4) of length up to 12, Preprint 2005.

Crossrefs

A110306 Number of inequivalent (indecomposable or decomposable) self-dual codes of Type {4^H+}_II and length 2n.

Original entry on oeis.org

1, 1, 2, 6, 21, 128, 3079
Offset: 0

Views

Author

N. J. A. Sloane, Sep 09 2005

Keywords

Crossrefs

A151827 Number of indecomposable self-dual additive codes of length n over GF(4) with minimal distance 4.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 5, 8, 120, 2506, 195455
Offset: 2

Views

Author

N. J. A. Sloane, Jul 12 2009

Keywords

Crossrefs

A105687 Number of inequivalent codes attaining highest minimal Hamming distance of any Type 4^H+ Hermitian additive self-dual code over GF(4) of length n.

Original entry on oeis.org

1, 1, 1, 3, 1, 1, 4, 5, 8, 120, 1, 1
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2005

Keywords

References

  • C. Bachoc and P. Gaborit, On extremal additive F_4 codes of length 10 to 18, in International Workshop on Coding and Cryptography (Paris, 2001), Electron. Notes Discrete Math. 6 (2001), 10 pp.
  • P. Gaborit, W. C. Huffman, J.-L. Kim and V. S. Pless, On additive GF(4) codes, in Codes and Association Schemes (Piscataway, NJ, 1999), A. Barg and S. Litsyn, eds., Amer. Math. Soc., Providence, RI, 2001, pp. 135-149.
  • G. Hoehn, Self-dual codes over the Kleinian four-group, Math. Ann. 327 (2003), 227-255.

Crossrefs

A016729 gives the minimal distance of these codes.
A094927 gives the number of inequivalent codes of any distance.

Extensions

Corrected and extended to 12 terms by Lars Eirik Danielsen (larsed(AT)ii.uib.no) and Matthew G. Parker (matthew(AT)ii.uib.no), Jun 30 2005

A151825 Number of indecomposable self-dual additive codes of length n over GF(4) with minimal distance 2.

Original entry on oeis.org

1, 1, 2, 3, 9, 22, 85, 363, 2436, 26750, 611036
Offset: 2

Views

Author

N. J. A. Sloane, Jul 12 2009

Keywords

Crossrefs

A151826 Number of indecomposable self-dual additive codes of length n over GF(4) with minimal distance 3.

Original entry on oeis.org

0, 0, 0, 1, 1, 4, 11, 69, 576, 11200, 467513
Offset: 2

Views

Author

N. J. A. Sloane, Jul 12 2009

Keywords

Crossrefs

A385629 Number of equivalence classes of connected 4-regular graphs on n unlabeled nodes up to local complementation.

Original entry on oeis.org

0, 0, 0, 0, 1, 1, 2, 6, 13, 56, 261
Offset: 1

Views

Author

Tristan Cam, Aug 09 2025

Keywords

Comments

Number of equivalences classes of 4-regular graphs on n nodes up to a sequence of local complementation or isomorphism.
a(n) is necessarily less than:
A033301(n) (number of non-isomorphic, not necessarily connected 4-regular graphs);
A006820(n) (number of non-isomophic connected 4-regular graphs);
A090899(n) (number of local equivalence classes of connected graphs); and
A156800(n) (number of equivalence classes for connected graphs up to pivots and isomorphism).
This is relevant in the study of optimal quantum circuit synthesis for graph state preparation.

Examples

			There are only two 4-regular graphs with 7 nodes and they are not equivalent up to a sequence of local complementation, thus a(7) = 2.
		

Crossrefs

A386962 Number of equivalence classes of connected 3-regular graphs on 2n unlabeled nodes up to local complementation.

Original entry on oeis.org

0, 1, 2, 4, 15, 60
Offset: 1

Views

Author

Tristan Cam, Aug 11 2025

Keywords

Comments

Number of equivalences classes of 3-regular graphs on 2n nodes up to a sequence of local complementation or isomorphism, also called orbits for the local equivalence relation.
a(n) is necessarily less than:
A005638(n) (number of non-isomorphic, not necessarily connected 3-regular graphs);
A002851(n) (number of non-isomophic connected 3-regular graphs);
A090899(n) (number of local equivalence classes of connected graphs); and
A156800(n) (number of equivalence classes for connected graphs up to pivots and isomorphism).
This is relevant in the study of optimal quantum circuit synthesis for graph state preparation.

Examples

			There are only two 3-regular graphs with 6 nodes and they are not equivalent up to a sequence of local complementation, thus a(3) = 2.
		

Crossrefs

Showing 1-9 of 9 results.