%I #4 Oct 27 2018 00:21:06
%S 1,3,5,6,8,10,12,13,15,17,18
%N An absolute lower bound on the number of components in perfect systems of difference sets (PSDS).
%D Abrham, J., and A. Kotzig. "Minimizing the number of components in perfect systems of difference sets." Congr. Numerantium, 47 (1985): 7-17. See Table 1, ceiling (h(c)).
%K nonn,more
%O 1,2
%A _N. J. A. Sloane_, Oct 27 2018