256470

Appears in sequences

• Values of k such that k - 1 and k + 1 are twin primes and 3*k^9 - 1 and 3*k^9 + 1 are also twin primes.at n=7A108134
• a(n) = n! * Sum_{k=0..n} (k * (n-k))^k/k!.at n=6A351795