72041

Appears in sequences

• a(n) = 1 + 4*n*(1 + 2*n^2)/3.at n=30A171272
• Euler pseudoprimes to base 3: composite integers such that abs(3^((n - 1)/2)) == 1 mod n.at n=36A262051
• Numbers k > 2 such that 3^(k-1) == 1 (mod k) and gcd(k, 2^(k-1)-1) = 1.at n=4A306144
• Super pseudoprimes (or superpseudoprimes) to base 3: Fermat pseudoprimes to base 3 all of whose divisors that are larger than 1 are either primes or Fermat pseudoprimes to base 3.at n=31A328662
• Odd numbers k > 1 such that gcd(3,k) = 1 and 3^((k-1)/2) == -(3/k) (mod k), where (3/k) is the Jacobi symbol (or Kronecker symbol); Euler pseudoprimes to base 3 (A262051) that are not Euler-Jacobi pseudoprimes to base 3 (A048950).at n=5A375490