99952737952domain: NAppears in sequencesNumber of (n+1)X(n+1) 0..3 arrays with the array of 2X2 subblock determinants symmetric.at n=3A187455T(n,k)=Number of (n+1)X(n+1) 0..k arrays with the array of 2X2 subblock determinants symmetric.at n=18A187457