600007domain: NAppears in sequencesSmallest n-digit number beginning with n and having prime signature of n, or 0 if no such number exists.at n=5A086558a(n) is the least semiprime > a(n-1) whose digits do not appear in a(n-1).at n=39A131220Smallest sequence which lists the position of digits "5" in the sequence.at n=42A167455