175781domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that cannot become a different prime under any mapping of some single decimal digit <=> with some other single decimal digit.at n=27A180561Dispersion of A016861, (5k+1), by antidiagonals.at n=37A191703a(n) = (9*5^n-1)/4.at n=7A198769Prime numbersat n=15971