1812389

Appears in sequences

• Numbers n such that 12^phi(n) == 1 (mod n^2), where phi(n) is Euler's totient function.at n=2A245529
• a(n) = smallest composite c such that n^(A000010(c)) == 1 (mod c^2), i.e., smallest composite Wieferich number to base n.at n=11A247154