490118

Appears in sequences

• a(n) is the n-th J_6-prime (Josephus_6 prime).at n=27A163786
• Smallest number k > 0 such that sigma(x) and sigma(x)+2 are both prime, where x = (6k+1)^(6n+4), or -1 if no such k exists.at n=27A275237