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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A076833 Triangle T(n,k) read by rows giving number of inequivalent projective binary linear [n,k] codes (n >= 1, 1 <= k <= n). 2
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 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,9

COMMENTS

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

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

Table of n, a(n) for n=1..83.

H. Fripertinger, Isometry Classes of Codes

Index entries for sequences related to binary linear codes

EXAMPLE

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; ...

CROSSREFS

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

Sequence in context: A026729 A109466 A259095 * A071676 A319933 A301570

Adjacent sequences:  A076830 A076831 A076832 * A076834 A076835 A076836

KEYWORD

nonn,tabl

AUTHOR

N. J. A. Sloane, Nov 21 2002

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 October 22 18:55 EDT 2018. Contains 316500 sequences. (Running on oeis4.)