%I #42 Jul 27 2020 04:00:51
%S 1,2,2,2,4,7,12,16
%N Size of minimal binary covering code of length n and covering radius 2.
%C Also the domination number of the (n+1)-halved cube graph. - _Eric W. Weisstein_, Aug 31 2016 and Jul 17 2017 (after discussion with Stan Wagon)
%D G. D. Cohen et al., Covering Codes, North-Holland, 1997, p. 166.
%H R. Bertolo, Patric R. J. Östergård and W. D. Weakley, <a href="http://dx.doi.org/10.1002/jcd.20008">An updated table of binary/ternary mixed covering codes</a>, J. Combin. Designs, 12 (2004), 157-176, DOI:10.1002/jcd.20008. [a(9)=16, bounds for n>9]
%H Dmitry Kamenetsky, <a href="/A029866/a029866.txt">Best known solutions for n <= 11.</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DominationNumber.html">Domination Number</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HalvedCubeGraph.html">Halved Cube Graph</a>
%H <a href="/index/Coa#covcod">Index entries for sequences related to covering codes</a>
%Y A column of A060438.
%Y Cf. A000983 (domination number of the n-hypercube graph Q_n).
%K nonn,more
%O 2,2
%A _N. J. A. Sloane_
%E a(9) from _Andrey Zabolotskiy_, Sep 01 2016