268501

Properties

Appears in sequences

• For p = prime(n), a(n) is the largest prime q such that pq is a base-2 pseudoprime; that is, 2^(pq-1) = 1 mod pq; a(n) is 0 if no such prime exists.at n=24A086019
• Primes whose logarithms are known to possess binary BBP formulas.at n=43A104885
• Largest prime factor of 4^(2*n+1)+1.at n=12A229747
• Largest prime factor of 2^(2*n+1)+2^(n+1)+1.at n=11A229768
• Largest prime factor of 4^n + 1.at n=25A274903
• a(n) = largest prime q such that q | 2^p - 2 and p - 1 | q - 1, where p = prime(n).at n=25A287945
• a(n) is the largest prime factor of 2^(prime(n) - 1) - 1.at n=24A358699
• Prime numbersat n=23518