133399

Appears in sequences

• Composite squarefree numbers k such that k^2-1 is divisible by p-1 and p+1, where p are all the prime factors of k.at n=9A306685
• Chebyshev pseudoprimes to both base 2 and base 3: composite numbers k such that T(k, 2) == 2 (mod k) and T(k, 3) == 3 (mod k), where T(k, x) is the k-th Chebyshev polynomial of the first kind.at n=11A330208
• Right-truncatable happy numbers: every prefix is a happy number and no digits are zero.at n=35A383638