27299

Properties

Appears in sequences

• a(n) is smallest safe prime (A005385) such that a(n) + 12*n is the next safe prime, i.e., x = (a(n) - 1)/2 and x + 6*n are closest Sophie Germain primes.at n=18A059327
• Primes which, although they have correct parity, are not in the prime number maze.at n=34A065123
• Highly cototient numbers that are prime, or intersection of A000040 and A100827.at n=40A105440
• Primes p such that q-p = 30, where q is the next prime after p.at n=32A124596
• Where records occur in A129385.at n=12A129387
• Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 3, read by rows.at n=37A157212
• Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 3, read by rows.at n=43A157212
• Safe primes that are also highly cototient numbers.at n=10A209193
• Numbers n such that (43^n - 1)/42 is prime.at n=4A240765
• Primes p such that q = p^2 + 10 and q^2 + 10 are also prime.at n=30A243368
• Primes having only {2, 7, 9} as digits.at n=32A261182
• a(n) = k if the last Dyck path that is counted in A279286(n) is the k-th Dyck path.at n=18A282198
• Relative of Hofstadter Q-sequence: a(n) = max(0, n+27298) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 0.at n=1A283888
• The number of even prime gaps g, satisfying g == 0 (mod 6), out of the first 2^n even prime gaps.at n=16A340948
• Primes p such that p^3 - 1 has 8 divisors.at n=28A341659
• Primes p such that if q is the next prime, p+A004086(q) and q+A004086(p) are prime.at n=35A351728
• Prime numbersat n=2989