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 1-3 of 3 results.

A076833 Triangle T(n,k) read by rows giving number of inequivalent projective binary linear [n,k] codes (n >= 1, 1 <= k <= n).

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 0, 2, 1, 0, 0, 1, 3, 1, 0, 0, 1, 4, 4, 1, 0, 0, 1, 5, 8, 5, 1, 0, 0, 0, 6, 15, 14, 6, 1, 0, 0, 0, 5, 29, 38, 22, 7, 1, 0, 0, 0, 4, 46, 105, 80, 32, 8, 1, 0, 0, 0, 3, 64, 273, 312, 151, 44, 9, 1, 0, 0, 0, 2, 89, 700, 1285, 821, 266, 59, 10, 1, 0, 0, 0, 1, 112
Offset: 1

Views

Author

N. J. A. Sloane, Nov 21 2002

Keywords

Comments

A code is projective if all columns are distinct and nonzero.

Examples

			1; 0,1; 0,1,1; 0,0,2,1; 0,0,1,3,1; 0,0,1,4,4,1; 0,0,1,5,8,5,1; ...

References

  • D. Slepian, Some further theory of group codes. Bell System Tech. J. 39 1960 1219-1252.
  • H. Fripertinger and A. Kerber, in AAECC-11, Lect. Notes Comp. Sci. 948 (1995), 194-204.

Links

Crossrefs

Cf. A076834 (row sums). Partial sums across rows gives triangle A091008.

A091008 Triangle T(n,k) read by rows giving number of inequivalent binary linear [n,k] codes with all columns distinct (projective codes) (n >= 1, 1 <= k <= n).

Original entry on oeis.org

1, 0, 1, 0, 1, 2, 0, 0, 2, 3, 0, 0, 1, 4, 5, 0, 0, 1, 5, 9, 10, 0, 0, 1, 6, 14, 19, 20, 0, 0, 0, 6, 21, 35, 41, 42, 0, 0, 0, 5, 34, 72, 94, 101, 102, 0, 0, 0, 4, 50, 155, 235, 267, 275, 276, 0, 0, 0, 3, 67, 340, 652, 803, 847, 856, 857, 0, 0, 0, 2, 91, 791, 2076, 2897
Offset: 1

Views

Author

N. J. A. Sloane, Mar 01 2004

Keywords

Links

Crossrefs

A076834 gives last diagonal. Running sums across rows of triangle A076833.

A076894 Number of inequivalent linear projective ternary codes of length n (i.e., with distinct columns and without zero columns). Also the number of nonisomorphic simple ternary matroids on an n-set.

Original entry on oeis.org

1, 1, 2, 4, 7, 17, 44, 141, 581, 3464, 33269, 582005
Offset: 1

Views

Author

Marcel Wild (mwild(AT)sun.ac.za), Nov 26 2002

Keywords

References

  • M. Wild, Enumeration of binary and ternary matroids and other applications of the Brylawski-Lucas Theorem, Preprint 1693, Technische Hochschule Darmstadt, 1994.

Links

Crossrefs

Cf. A076834, A076893.

Extensions

a(11)-a(12) from Fripertinger's table added by Andrei Zabolotskii, Aug 27 2025
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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