306320

Appears in sequences

• T(n,k)=Number of (n+1)X(n+1) 0..k arrays with the array of 2X2 subblock determinants antisymmetric under horizontal and vertical reflection and each non-centerline 2X2 subblock nonsingular.at n=23A187633
• Number of 4X4 0..n arrays with the array of 2X2 subblock determinants antisymmetric under horizontal and vertical reflection and each non-centerline 2X2 subblock nonsingular.at n=4A187634
• Number of (w,x,y,z) with all terms in {1,...,n} and w<2x and y<=2z.at n=27A212507