%I A011980
%S A011980 1,4,5,8,12,17,20
%N A011980 Covering numbers C(n,5,3) (next term is <= 29).
%D A011980 CRC Handbook of Combinatorial Designs, 1996, p. 262.
%H A011980 D. Gordon, <a href="http://www.ccrwest.org/cover.html">La Jolla Repository 
               of Coverings</a>
%H A011980 <a href="Sindx_Cor.html#covnum">Index entries for covering numbers</a>
%Y A011980 Sequence in context: A130814 A047609 A027975 this_sequence A061765 A133940 
               A030978
%Y A011980 Adjacent sequences: A011977 A011978 A011979 this_sequence A011981 A011982 
               A011983
%K A011980 nonn,hard
%O A011980 5,2
%A A011980 N. J. A. Sloane (njas(AT)research.att.com).