3387715318

Appears in sequences

• Number of (n+1)X(n+1) 0..3 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.at n=3A187460
• T(n,k)=Number of (n+1)X(n+1) 0..k arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.at n=18A187462
• Number of 5X5 0..n arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.at n=2A187465