

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
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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 12191252.
H. Fripertinger and A. Kerber, in AAECC11, Lect. Notes Comp. Sci. 948 (1995), 194204.


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: A109466 A259095 A326676 * A071676 A319933 A301570
Adjacent sequences: A076830 A076831 A076832 * A076834 A076835 A076836


KEYWORD

nonn,tabl


AUTHOR

N. J. A. Sloane, Nov 21 2002


STATUS

approved



