270343

Properties

Appears in sequences

• Indices of prime repunits: numbers k such that 11...111 (with k 1's) = (10^k - 1)/9 is prime.at n=8A004023
• s(n+3)/2, where s is A024945.at n=20A024946
• a(n) = 33*2^(n+1) + 7.at n=12A196655
• Primes of the form 33*2^n + 7.at n=6A196656
• Numbers n such that (10^n-1)/9 is prime and can be written in the form a^2 + 3*b^2.at n=3A216529
• Numbers k such that 11...111 (with k 1's) = (10^k - 1)/9 is a Kaprekar prime.at n=2A350755
• Prime numbersat n=23674