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A066009
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Covering numbers C(n,7,6).
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3
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OFFSET
| 7,2
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COMMENTS
| C(v,k,t) is the smallest number of k-subsets of an n-set such that every t-subset is contained in at least one of the k-subsets.
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REFERENCES
| CRC Handbook of Combinatorial Designs, 1996, p. 263.
W. H. Mills and R. C. Mullin, Coverings and packings, pp. 371-399 of J. H. Dinitz and D. R. Stinson, editors,a Contemporary Design Theory, Wiley, 1992.
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LINKS
| D. Applegate, E. M. Rains and N. J. A. Sloane, On asymmetric coverings and covering numbers, J. Comb. Des. 11 (2003), 218-228.
D. Gordon, La Jolla Repository of Coverings
K. J. Nurmela and P. R. J. Ostergard, New coverings of t-sets with (t+1)-sets, J. Combinat. Designs, 7 (1999), 217-226.
K. J. Nurmela and P. R. J. Ostergard, New coverings of t-sets with (t+1)-sets (appendix), J. Combinat. Designs, 7 (1999), 217-226.
Index entries for covering numbers
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CROSSREFS
| Cf. A011983. A column of A066010.
Sequence in context: A020941 A024625 A055553 * A037241 A154141 A173661
Adjacent sequences: A066006 A066007 A066008 * A066010 A066011 A066012
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KEYWORD
| nonn,hard
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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