Number of (n+1)X(n+1) 0..1 arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal.
A187668
Number of (n+1)X(n+1) 0..1 arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal.
Terms
- a(0) =6a(1) =24a(2) =112a(3) =974a(4) =9928a(5) =197152a(6) =4547688a(7) =200947508a(8) =10553936856
External references
- oeis: A187668