A183363 - OEIS

%I #6 Dec 18 2015 18:17:28

%S 1,3,18,138,3102,137688,12617557,2402945556,936460285557,

%T 739951660291721

%N Number of n X n binary arrays with no element equal to the sum mod 3 of its horizontal and vertical neighbors

%C Diagonal of A183368

%e Some solutions for 5X5

%e ..1..0..0..1..1....1..1..1..0..0....1..1..1..1..0....1..1..0..0..1

%e ..0..0..1..1..1....1..0..1..0..1....1..0..0..1..0....1..1..1..0..0

%e ..1..0..1..0..1....1..1..1..0..0....1..0..0..1..1....1..0..1..1..1

%e ..0..0..1..1..1....0..0..1..1..1....1..1..1..1..1....1..1..0..1..1

%e ..1..0..1..1..1....1..0..1..1..1....1..1..0..0..0....0..1..1..1..0

%K nonn

%O 1,2

%A _R. H. Hardin_ Jan 04 2011