%I A003509 M0833
%S A003509 2,3,7,13,21,31
%N A003509 A problem in (0,1)-matrices.
%D A003509 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A003509 Problem E2429, Amer. Math. Monthly, 81 (1974), 1112-1113.
%H A003509 <a href="Sindx_Mat.html#binmat">Index entries for sequences related to 
               binary matrices</a>
%Y A003509 Sequence in context: A070754 A049887 A048216 this_sequence A133370 A144104 
               A088175
%Y A003509 Adjacent sequences: A003506 A003507 A003508 this_sequence A003510 A003511 
               A003512
%K A003509 nonn
%O A003509 2,1
%A A003509 N. J. A. Sloane (njas(AT)research.att.com).