72938

Appears in sequences

• Numbers k such that k*10^10-1, k*10^10-3, k*10^10-7 and k*10^10-9 are all prime.at n=1A064981
• Triangle read by rows: T(n,k) = arithmetic derivative of (1 + A002110(n) + A002110(k)), 1 <= k <= n, where A002110(n) is the n-th primorial number.at n=22A373845