2582449

Appears in sequences

• Numbers k such that concat(k, d(k)) and concat(d(k), k) are both prime, where d(k) is the number of divisors of k.at n=23A284643
• a(n) = A379119(A379121(n)), where A379121 gives those odd squares k for which A379113(k) > 1 and A379119(n) = n/A379113(n).at n=32A379124