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 1-10 of 19 results. Next

A066016 Highest minimal Hamming distance of any Type 4^Z self-dual code of length n over Z/4Z.

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 3, 4, 1, 2, 2, 2, 2, 3, 3, 4, 4, 4, 3, 4, 5, 6, 7, 8
Offset: 1

Views

Author

N. J. A. Sloane, Dec 12 2001; revised May 06 2005

Keywords

Crossrefs

Cf. A066017 for number of codes. See also A066012-A066017, A098068.

A105676 Highest minimal Hamming distance of any Type 3 ternary self-dual code of length 4n.

Original entry on oeis.org

3, 3, 6, 6, 6, 9, 9, 9, 12, 12, 12, 15, 15, 15, 18, 18
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2005

Keywords

Examples

			The [12,6,6]_3 ternary Golay code has d=6, so a(3) = 6.
		

References

  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1977.

Crossrefs

Extensions

The sequence continues: a(17) = either 15 or 18, a(18) = 18, ...

A105682 Highest minimal Euclidean norm of any Type 4^Z self-dual code of length n over Z/4Z.

Original entry on oeis.org

4, 4, 4, 4, 4, 4, 4, 8, 4, 4, 4, 8, 4, 8, 8, 8, 8, 8, 8, 8, 8, 8, 12, 16
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2005

Keywords

Crossrefs

A105689 gives number of such codes. Cf. also A066014.

A016729 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, 2, 2, 2, 3, 4, 3, 4, 4, 4, 5, 6, 5, 6, 6, 6, 7, 8, 7, 8, 8, 8
Offset: 1

Views

Author

N. J. A. Sloane. Entry revised May 06 2005

Keywords

Comments

The sequence continues: a(23) = 8 or 9, a(24) = 8, 9 or 10, a(25) = 8 or 9, ...

References

  • P. Gaborit and A. Otmani, Experimental construction of self-dual codes, Preprint.

Crossrefs

A105687 gives the number of codes with this minimal distance.

Formula

Conjectures from Chai Wah Wu, Apr 13 2024: (Start)
a(n) = a(n-1) + a(n-6) - a(n-7) for n > 7.
G.f.: x*(-2*x^6 + x^5 + x^4 + x + 1)/(x^7 - x^6 - x + 1). (End)

A105675 Highest minimal distance of any Type II doubly-even binary self-dual code of length 8n.

Original entry on oeis.org

4, 4, 8, 8, 8, 12, 12, 12
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2005

Keywords

Comments

Is a(9) = 12 or 16? This is an open question of long standing.

Examples

			At length 8 the only Type II doubly-even self-dual code is the Hamming code e_8, which has d=4, so a(1) = 4. The [24,12,8] Golay code has d=8, so a(3) = 8.
		

References

  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1977.

Crossrefs

A105677 Highest minimal Hamming distance of any Type 4^E Euclidean linear self-dual code over GF(4) of length 2n.

Original entry on oeis.org

2, 3, 3, 4, 4, 6, 6, 6
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2005

Keywords

Comments

There is a related sequence which is presently too short to include: Highest minimal Lee distance of any Type (4^E)_II Euclidean linear even self-dual code over GF(4) of length 4n. This begins 4, 4, 8, 8, 8, then either 8 or 12, 12, 12, ...
The sequence continues: a(9) = either 6 or 7, a(10) = a(11) = 8, a(12) = 8, 9 or 10, ...

References

  • P. Gaborit and A. Otmani, Experimental construction of self-dual codes, Preprint.

Crossrefs

A105678 Highest minimal Hamming distance of any Type 4^H Hermitian linear self-dual code over GF(4) of length 2n.

Original entry on oeis.org

2, 2, 4, 4, 4, 4, 6, 6, 8, 8, 8, 8, 8, 10, 12
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2005

Keywords

Comments

The next term a(16) is either 10 or 12.

Crossrefs

Cf. also A105686 for the numbers of such codes.

A105681 Highest minimal Lee distance of any Type 4^Z self-dual code of length n over Z/4Z.

Original entry on oeis.org

2, 2, 2, 4, 2, 4, 4, 6, 2, 4, 4, 4, 4, 6, 6, 8, 6, 8, 6, 8, 8, 8, 10, 12
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2005

Keywords

Crossrefs

See A105688 for the number of such codes. Cf. also A066012.

A066012 Highest minimal Lee distance of any Type 4^Z self-dual code of length n over Z/4Z which does not have all Euclidean norms divisible by 8, that is, is strictly Type I. Compare A105681.

Original entry on oeis.org

2, 2, 2, 4, 2, 4, 4, 4, 2, 4, 4, 4, 4, 6, 6, 8, 6, 8, 6, 8, 8, 8, 10, 10
Offset: 1

Views

Author

N. J. A. Sloane, Dec 11 2001

Keywords

Crossrefs

Cf. A066013 for number of codes. See also A066014-A066017.

A066017 Number of inequivalent codes attaining highest minimal Hamming distance of any Type 4^Z self-dual code of length n over Z/4Z.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 1, 11, 5, 3, 39, 8, 4, 47
Offset: 1

Views

Author

N. J. A. Sloane, Dec 12 2001; revised May 06 2005

Keywords

Comments

There are two versions of this sequence, this and A111259. I am not sure which is correct.

Crossrefs

Cf. A066015 for minimal distance. See also A066012-A066016.
Showing 1-10 of 19 results. Next