94212domain: NAppears in sequencesNumber of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 11011-01110-00100 pattern in any orientation.at n=16A147483Numbers k such that 4*R_k + 7*10^k + 3 is prime, where R_k = 11...11 is the repunit (A002275) of length k.at n=10A259136