%I #6 Dec 18 2015 18:17:42
%S 0,0,20,1436,175145,47175440,29471424170,42983780102348,
%T 146444614636063181,1165528963228211645900,21669813287663490052945610,
%U 941174635410184709958677112920,95492317441878724418372856301818197
%N Number of n X n symmetric 0..3 arrays with no element equal to any horizontal or vertical neighbor, containing at least one 3 and with new values 0..3 introduced in lower triangular row major order
%H R. H. Hardin, <a href="/A193309/b193309.txt">Table of n, a(n) for n = 1..15</a>
%e Some solutions for 4X4
%e ..0..1..0..1....0..1..3..0....0..1..3..1....0..1..2..0....0..1..3..1
%e ..1..2..1..3....1..2..0..2....1..2..1..3....1..2..3..2....1..2..1..3
%e ..0..1..0..2....3..0..3..0....3..1..0..2....2..3..2..3....3..1..2..1
%e ..1..3..2..1....0..2..0..3....1..3..2..3....0..2..3..0....1..3..1..2
%K nonn
%O 1,3
%A _R. H. Hardin_ Jul 22 2011