[go: up one dir, main page]

login
A066009
Covering numbers C(n,7,6).
3
1, 7, 16, 45, 84
OFFSET
7,2
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.
REFERENCES
CRC Handbook of Combinatorial Designs, 1996, p. 263.
W. H. Mills and R. C. Mullin, Coverings and packings, pp. 371-399 of Jeffrey H. Dinitz and D. R. Stinson, editors, Contemporary Design Theory, Wiley, 1992.
LINKS
D. Applegate, E. M. Rains and N. J. A. Sloane, On asymmetric coverings and covering numbers, J. Comb. Des. 11 (2003), 218-228.
K. J. Nurmela and Patric R. J. Östergård, New coverings of t-sets with (t+1)-sets, J. Combinat. Designs, 7 (1999), 217-226.
K. J. Nurmela and Patric R. J. Östergård, New coverings of t-sets with (t+1)-sets (appendix), J. Combinat. Designs, 7 (1999), 217-226.
CROSSREFS
Cf. A011983. A column of A066010.
Sequence in context: A318750 A024625 A055553 * A304013 A037241 A154141
KEYWORD
nonn,hard
STATUS
approved