A018200 - OEIS

%I #10 Dec 12 2015 00:29:27

%S 1,8,49,128,216,255,512

%N Possible numbers of complements of topologies on 9 points.

%H J. I. Brown and S. Watson, <a href="http://dx.doi.org/10.1016/0012-365X(95)00004-G">The number of complements of a topology on n points is at least 2^n (except for some special cases)</a>, Discr. Math., 154 (1996), 27-39.

%K nonn,more

%O 0,2

%A _N. J. A. Sloane_