146590domain: NAppears in sequences100000n+1, 100000n+3, 100000n+7, 100000n+9 are all primes.at n=27A064964Number of n-digit primes ending in 7 in base 10.at n=6A087632a(n) = the frequency of the most common final digit of a prime with n digits.at n=6A244253