%I #4 Feb 04 2019 14:14:44
%S 3,79,457645
%N Number of ways to choose 2^n vectors in {0, 1, 2, 3}^n such that any two differ by at least 2 in at least one coordinate (2^n being maximal).
%K nonn,bref,hard
%O 1,1
%A _Jan Kristian Haugland_