778261

Appears in sequences

• Composite squarefree numbers k such that p+1 divides k-1 for any prime p dividing k.at n=33A225711
• 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=27A330208