T(n,k)=Number of nXk 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(k+1) binary array having nonzero determinant, with rows and columns of the latter in lexicographically nondecreasing order.

A227558

T(n,k)=Number of nXk 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(k+1) binary array having nonzero determinant, with rows and columns of the latter in lexicographically nondecreasing order.