8831418697

Appears in sequences

• Largest primitive factor of 2^(2n+1) + 1.at n=20A002589
• 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=21A086019
• Irregular triangle in which row n has all primes q such that prime(n)*q is a base-2 Fermat pseudoprime.at n=40A180471
• Largest prime factor of the n-th Jacobsthal number, A001045(n).at n=38A271314
• a(n) = largest prime q such that q | 2^p - 2 and p - 1 | q - 1, where p = prime(n).at n=22A287945
• a(n) is the largest prime factor of 2^(prime(n) - 1) - 1.at n=21A358699