A066040 Triangle of covering numbers T(n,k) = C(n,k,k-3), n >= 4, 4 <= k <= n.

1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 4, 4, 5, 1, 3, 5, 7, 6, 6, 1, 3, 6, 10, 10, 8, 7, 1, 3, 7, 11, 17, 16, 10, 8, 1

Offset

4,2

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

Table of n, a(n) for n=4..39.

D. Gordon, La Jolla Repository of Coverings

Index entries for covering numbers

Example

1; 2 1; 2 3 1; 2 3 4 1; 2 4 4 5 1; ...

Crossrefs

Sequence in context: A329288 A181845 A183534 * A318806 A066019 A051237

Adjacent sequences: A066037 A066038 A066039 * A066041 A066042 A066043

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, Dec 30 2001

Status

approved