%I #5 Aug 11 2014 22:46:10
%S 1584,14564,133528,1282504,12149024,115206520,1092851528,10375258140,
%T 98442896216,934214824740,8864965437532,84126729220500,
%U 798309064976816,7575648390881364,71889164102413344,682196900350785372
%N Number of (n+1)X(2+1) 0..3 arrays with the upper median plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one
%C Column 2 of A237921
%H R. H. Hardin, <a href="/A237916/b237916.txt">Table of n, a(n) for n = 1..210</a>
%H R. H. Hardin, <a href="/A237916/a237916.txt">Empirical recurrence of order 56</a>
%F Empirical recurrence of order 56 (see link above)
%e Some solutions for n=3
%e ..0..2..0....2..0..3....1..2..2....2..2..0....0..3..1....2..1..0....1..0..0
%e ..2..3..1....1..1..2....2..0..2....1..1..1....1..0..1....2..1..2....1..2..1
%e ..1..3..1....2..2..3....2..3..1....3..0..0....1..3..2....2..3..1....2..0..1
%e ..2..2..0....3..0..1....3..2..2....1..0..1....1..2..2....0..1..0....3..0..2
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 15 2014