%I #7 Mar 30 2012 16:49:17
%S 1,2,3,6,10,18,31,58
%N Size of smallest directed 1-covering code of length n.
%C Minimal binary code C of length n such that every vector of length n is either in the code or is obtained from a codeword by changing a single 1 to a 0.
%H 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 E. M. Rains and N. J. A. Sloane, <a href="/A066000/a066000.txt">Examples of codes of lengths 1 through 8</a>
%H <a href="/index/Coa#covcod">Index entries for sequences related to covering codes</a>
%e n=4: C = {1111, 1110, 0111, 1001, 0100, 0010}.
%Y Cf. A019436.
%K nonn,nice,more
%O 1,2
%A _N. J. A. Sloane_, Dec 07 2001