4800307

Appears in sequences

• a(1) = 1, a(n) = smallest number > a(n-1) such that concatenation a(k) a(n) is prime for all k = 1 to n-1. Stop if no such number exists.at n=8A075611
• a(1) = 1, then the smallest number such that the concatenation a(r), a(s) is prime for all s > r.at n=9A088647