Number of (n+1)X(n+1) 0..4 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.
A187404
Number of (n+1)X(n+1) 0..4 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.
Terms
- a(0) =25a(1) =1751a(2) =426425a(3) =397056235
External references
- oeis: A187404