121647domain: NAppears in sequencesNumber of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 11011-01110-00100 pattern in any orientation.at n=19A147485G.f. satisfies: A(x) = (1 + x*(1-x)*A(x)) * (1 + x^2*A(x)^2).at n=14A216616