Number of (n+1)X(n+1) 0..3 arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under horizontal and vertical reflection.
A187698
Number of (n+1)X(n+1) 0..3 arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under horizontal and vertical reflection.
Terms
- a(0) =192a(1) =74a(2) =87258a(3) =22738a(4) =1089964504
External references
- oeis: A187698