%I #4 Feb 16 2014 06:49:42
%S 1494,10014,59014,357672,2270776,14222512,88114176,550642732,
%T 3451069630,21560822458,134629301012,841895591970,5264528244482,
%U 32900378176060,205627745431856,1285545369352008,8036253217579508,50230256232200120
%N Number of (n+1)X(2+1) 0..3 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one
%C Column 2 of A237974
%H R. H. Hardin, <a href="/A237968/b237968.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 84*a(n-3) +773*a(n-4) +1372*a(n-5) +3600*a(n-6) -8931*a(n-7) -55854*a(n-8) -94782*a(n-9) -31846*a(n-10) +191731*a(n-11) +369506*a(n-12) +355656*a(n-13) +149556*a(n-14) +448480*a(n-15) +642040*a(n-16) +99840*a(n-17) for n>20
%e Some solutions for n=3
%e ..2..1..0....1..1..0....0..3..0....0..2..1....3..1..2....3..2..0....1..1..0
%e ..1..2..1....1..3..2....1..2..3....1..0..3....0..1..2....2..3..1....2..3..1
%e ..1..1..2....0..2..3....0..1..0....2..3..2....0..0..0....0..1..1....3..0..2
%e ..2..3..3....0..1..0....2..3..1....3..1..1....3..1..0....1..2..2....2..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 16 2014