A209943 - OEIS

%I #6 Mar 31 2012 12:37:30

%S 34,4975,4681176,28414622976,1111386232102422,280228918282467201434,

%T 455417252425855582254656088,4770739366042378532001509022194668,

%U 322127888969925272433863054772450693097784

%N Half the number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock having at most one duplicate clockwise edge difference

%C Diagonal of A209951

%H R. H. Hardin, <a href="/A209943/b209943.txt">Table of n, a(n) for n = 1..11</a>

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 16 2012