109297

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=7A004023
• Number of primitive subsequences of {1, 2, ..., n}.at n=25A051026
• Numbers n such that (10^n-1)/9 is prime and can be written in the form a^2 + 3*b^2.at n=2A216529
• Primes of the form x^3 + y^3 - 1, where x and y are primes.at n=23A217718
• Expansion of Product_{k>=1} 1/(1 - x^k)^(k*(3*k-1)/2).at n=12A278768
• Prime numbers which can be expressed as the sum of two numbers, one of which is the rotationally ambigrammatic transformation of the other excluding leading zeros.at n=30A340054
• Numbers k such that 11...111 (with k 1's) = (10^k - 1)/9 is a Kaprekar prime.at n=1A350755
• Prime numbersat n=10390