Number of (n+1)X(n+1) 0..6 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.
A187406
Number of (n+1)X(n+1) 0..6 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.
Terms
- a(0) =49a(1) =9331a(2) =8583967a(3) =41906480269
External references
- oeis: A187406