A187931 - OEIS

%I #5 Mar 31 2012 12:36:09

%S 48,104,7616,544222,167909728

%N Number of (n+2)X(n+2) binary arrays with every 2X2 subblock sum equal to some diagonal or antidiagonal neighbor 2X2 subblock sum

%C Diagonal of A187940

%e Some solutions for 4X4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 16 2011