249841

Appears in sequences

• Brilliant Sarrus numbers.at n=21A086837
• Fermat pseudoprimes (A001567) that are the sum of three consecutive primes.at n=4A270639
• Numbers k such that 2^(k-1) == 1 (mod k) and lpf(k)-1 does not divide k-1.at n=13A316906
• Numbers k such that 2^(k-1) == 1 (mod k) and p-1 does not divide k-1 for every prime p dividing k.at n=11A316907