1118854

Appears in sequences

• 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=22A187462
• Number of 3X3 0..n arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.at n=5A187463
• a(n) = Catalan(n) mod Fibonacci(n).at n=30A246846