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, with rows and columns of the latter in nondecreasing lexicographic order.

A227636

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, with rows and columns of the latter in nondecreasing lexicographic order.