%I #5 Dec 18 2015 18:18:38
%S 2,13,210,10092,1378923,536234494,593219255593,1866485946679255,
%T 16707964949615383863,425495289603079437453771,
%U 30826893520750966059187346452
%N Number of n X n 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(n+1) binary array having determinant equal to one
%C Diagonal of A227751
%e Some solutions for n=4
%e ..1..0..0..1....1..0..0..1....1..0..1..0....0..1..0..1....0..0..1..0
%e ..0..0..0..1....0..0..0..0....0..0..0..0....0..0..1..0....1..0..1..0
%e ..1..0..0..0....0..0..0..0....1..0..1..0....0..0..1..0....1..1..0..1
%e ..1..1..0..1....0..0..1..0....0..1..0..1....0..1..0..0....0..0..0..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Jul 25 2013