121525356464domain: NAppears in sequencesNumber of (n+1)X(n+1) 0..1 arrays with the array of 2X2 subblock determinants symmetric.at n=5A187453T(n,k)=Number of (n+1)X(n+1) 0..k arrays with the array of 2X2 subblock determinants symmetric.at n=20A187457