Number of (n+1)X(n+1) 0..1 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
A187458
Number of (n+1)X(n+1) 0..1 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Terms
- a(0) =6a(1) =26a(2) =144a(3) =1272a(4) =15192a(5) =286392a(6) =7648032a(7) =314011868a(8) =18986004296
External references
- oeis: A187458