%I #6 Mar 31 2012 12:37:04

%S 256,13116,4251766,6997750028,56016870922512,2198408614173601972,

%T 426069670428664499911552,408397032103596887991434131888,

%U 1937279907224716538436705741462507484

%N Number of (n+1)X(n+1) 0..3 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock equal to the number in all its horizontal and vertical neighbors

%C Diagonal of A205097

%H R. H. Hardin, <a href="/A205089/b205089.txt">Table of n, a(n) for n = 1..10</a>

%e Some solutions for n=4

%e ..3..1..2..0..1....1..3..3..1..0....2..2..3..0..3....1..1..0..2..1

%e ..2..3..2..3..0....0..0..3..3..0....0..3..1..2..2....0..3..1..0..2

%e ..3..1..3..0..2....1..0..0..1..1....3..2..3..0..3....2..1..2..2..0

%e ..0..3..0..3..2....1..1..0..0..1....2..3..0..3..2....0..3..0..3..2

%e ..1..0..1..1..3....3..1..1..0..0....3..0..3..1..3....1..0..1..1..3

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 22 2012