A193500 - OEIS

%I #5 Dec 18 2015 18:17:42

%S 4,30,476,16922,1328430,224738251,82830799570,66307508721755,

%T 115414300257319497,435721788093736397288,3576788708181112341917385,

%U 63678865525598948282213562255,2464034493065067438484568541197974

%N Number of n X n symmetric 0..3 arrays with no element equal to the product mod 4 of any two of its horizontal and vertical neighbors

%e Some solutions for 4X4

%e ..3..0..1..1....2..0..1..3....0..3..3..3....3..0..3..2....3..3..3..2

%e ..0..2..3..2....0..3..1..0....3..0..3..3....0..3..0..1....3..3..3..0

%e ..1..3..2..1....1..1..0..3....3..3..3..0....3..0..3..2....3..3..2..3

%e ..1..2..1..2....3..0..3..2....3..3..0..1....2..1..2..3....2..0..3..2

%K nonn

%O 1,1

%A _R. H. Hardin_ Jul 29 2011