%I #7 Nov 24 2018 08:14:05
%S 4,4,4,5,4,6,4,4,4
%N Minimal size of a complete cap in (Z/nZ)^2.
%C A line in (Z/nZ)^2 is any translate of a cyclic subgroup of order n. A subset X of (Z/nZ)^2 is a cap if no three of its points are collinear and X is complete if it is not properly contained in another cap. a(n) is the minimal size of a complete cap in (Z/nZ)^2.
%H Jack Huizenga, <a href="http://www.combinatorics.org/ojs/index.php/eljc/article/view/v13i1r58">The Minimum Size of Complete Caps in (Z/nZ)^2</a>, Electron. J. Combin., 13 (2006), #R58.
%F If p is the smallest prime divisor of n, max{4, sqrt2p+1/2} <= a(n) <= max{4,p+1}. a(n) = 4 if n is divisible by 2 or 3.
%K nonn,more
%O 2,1
%A _N. J. A. Sloane_, Aug 01 2006