%I
%S 256,1494,7905,40442,208210,1074202,5540337,28475040,146747184,
%T 755218808,3893371264,20027524168,103232219796,531114565248,
%U 2737826075360,14084875246240,72603362037280,373519603204256,1925412625288848
%N Number of (n+1)X(1+1) 0..3 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one
%C Column 1 of A237974
%H R. H. Hardin, <a href="/A237967/b237967.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 488*a(n4) +5140*a(n6) +14624*a(n8) +12288*a(n10) for n>13
%e Some solutions for n=4
%e ..3..0....0..3....2..1....2..1....2..0....3..3....3..2....2..2....3..2....3..0
%e ..2..3....1..3....1..0....0..3....3..2....3..2....3..2....3..1....0..1....0..0
%e ..2..1....2..1....0..0....3..2....3..0....1..1....1..0....0..0....0..2....1..2
%e ..1..0....1..1....2..1....1..2....2..0....0..0....0..3....3..2....0..0....3..1
%e ..2..2....2..3....1..3....1..0....3..3....0..1....0..0....3..0....1..3....0..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 16 2014
