%I A066009
%S A066009 1,7,16,45,84
%N A066009 Covering numbers C(n,7,6).
%C A066009 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.
%D A066009 CRC Handbook of Combinatorial Designs, 1996, p. 263.
%D A066009 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.
%H A066009 D. Applegate, E. M. Rains and N. J. A. Sloane, <a href="http://arXiv.org/
               abs/math.CO/0205303">On asymmetric coverings and covering numbers</
               a>, J. Comb. Des. 11 (2003), 218-228.
%H A066009 D. Gordon, <a href="http://www.ccrwest.org/cover.html">La Jolla Repository 
               of Coverings</a>
%H A066009 K. J. Nurmela and P. R. J. Ostergard, <a href="http://www.tcs.hut.fi/
               old/papers/tp1.ps.Z">New coverings of t-sets with (t+1)-sets</a>, 
               J. Combinat. Designs, 7 (1999), 217-226.
%H A066009 K. J. Nurmela and P. R. J. Ostergard, <a href="http://www.tcs.hut.fi/
               old/papers/table3.html">New coverings of t-sets with (t+1)-sets (appendix)</
               a>, J. Combinat. Designs, 7 (1999), 217-226.
%H A066009 <a href="Sindx_Cor.html#covnum">Index entries for covering numbers</a>
%Y A066009 Cf. A011983. A column of A066010.
%Y A066009 Sequence in context: A020941 A024625 A055553 this_sequence A037241 A154141 
               A152530
%Y A066009 Adjacent sequences: A066006 A066007 A066008 this_sequence A066010 A066011 
               A066012
%K A066009 nonn,hard
%O A066009 7,2
%A A066009 N. J. A. Sloane (njas(AT)research.att.com).