Number of (n+1)X(n+1) 0..2 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.
A187402
Number of (n+1)X(n+1) 0..2 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.
Terms
- a(0) =9a(1) =141a(2) =4743a(3) =378999a(4) =77470101a(5) =43182942669
External references
- oeis: A187402