704477domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1111-0010-0010 pattern in any orientation.at n=19A147174Primes having only {0, 4, 7} as digits.at n=29A384449Prime numbersat n=56883