%I #5 Mar 31 2012 12:37:34
%S 4,157,34848,32087451,116765092684,1675364225009869,
%T 94777043088521233200,21139495208799287816738519,
%U 18590180528543794272963690721687,64457007550068881643906256762264646455
%N Number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having two, three or four distinct values, and new values 0..3 introduced in lower triangle row major order
%H R. H. Hardin, <a href="/A210837/b210837.txt">Table of n, a(n) for n = 1..13</a>
%e Some solutions for n=3
%e ..0..1..3..0....0..1..0..1....0..1..3..3....0..1..1..0....0..1..1..1
%e ..1..2..3..2....1..1..0..0....1..2..3..0....1..0..0..0....1..2..2..2
%e ..3..3..1..3....0..0..2..1....3..3..2..3....1..0..1..2....1..2..0..0
%e ..0..2..3..1....1..0..1..0....3..0..3..2....0..0..2..0....1..2..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 27 2012