A209806 - OEIS

%I #5 Mar 31 2012 12:37:30

%S 7,302,43209,20873080,32449786403,163050586738067,2632434564856390561,

%T 137193223429735040307661

%N Number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having two distinct values, and new values 0..3 introduced in row major order

%C Diagonal of A209814

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 13 2012