A237559 - OEIS

%I #4 Feb 09 2014 06:53:44

%S 81,1536,44828,2161168,159014170,18615658788,3615152813462,

%T 1107896271684848

%N Number of (n+1)X(n+1) 0..2 arrays with the upper median plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

%C Diagonal of A237567

%e Some solutions for n=3

%e ..1..1..0..0....0..1..2..2....0..1..2..2....0..2..1..0....1..2..0..2

%e ..1..2..2..2....1..0..1..1....0..1..1..1....2..2..1..2....0..0..2..1

%e ..2..0..0..1....1..2..0..1....1..2..2..1....1..1..0..0....2..0..1..1

%e ..1..1..1..2....0..2..0..1....2..0..0..2....1..0..1..0....1..0..0..0

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 09 2014