131977

Appears in sequences

• Strong pseudoprimes to base 12.at n=36A020238
• Semiprimes k such that k+4, k+6, k+9, k+10 and k+14 are also semiprimes.at n=33A360666
• Odd numbers k > 1 such that gcd(5,k) = 1 and 5^((k-1)/2) == -(5/k) (mod k), where (5/k) is the Jacobi symbol (or Kronecker symbol); Euler pseudoprimes to base 5 (A262052) that are not Euler-Jacobi pseudoprimes to base 5 (A375914).at n=11A375816