210165

Appears in sequences

• Numbers k such that 2k+1, 4k+1, 6k+1, 8k+1 and 10k+1 are primes.at n=14A124410
• a(n) = number of terms in A213717 whose magnitude is in range [(2^n)-1,(2^(n+1))-2] (or equally, in range [(2^n),(2^(n+1))-1]).at n=19A213722