616318177

Properties

Appears in sequences

• a(n) = largest noncomposite factor of 2^(2n+1) - 1.at n=18A002588
• Largest prime factor of n-th Mersenne number (A001348(n)).at n=11A003260
• Largest prime factor of 2^n - 1.at n=35A005420
• Second prime factor, if it exists, of Mersenne numbers.at n=3A089158
• Triangle read by rows formed by the prime factors of Mersenne number 2^prime(n) - 1, n >= 1.at n=16A089162
• Largest primitive prime factor of 2^n-1, or a(n) = 1 if no such prime exists.at n=36A097406
• Sort the primes (except 2) according to the multiplicative order of 2 modulo that prime. If two primes have the same order of 2, they are arranged numerically.at n=43A108974
• Largest prime factor of composite Mersenne numbers.at n=3A136031
• Sturdy prime numbers: p such that in binary notation k*p has at least as many 1-bits as p for all k > 0.at n=19A143027
• a(n) is the largest proper divisor of the Mersenne composite A065341(n).at n=3A145097
• Duplicate of A136031.at n=3A145098
• Primes p such that (p-1)/ord(2,p) > (q-1)/ord(2,q) for odd primes q < p.at n=34A226216
• Prime factors of 2^A054723(n)-1, ordered by increasing n, then by increasing size of the factors.at n=8A244453
• Minimum of the greatest prime factors of (i^prime(n)-1)/(i-1), when i runs through all integers in [2, prime(n)].at n=11A247229
• Largest prime factor of 4^n - 1.at n=36A274906
• a(n) = largest prime q such that q | 2^p - 2 and p - 1 | q - 1, where p = prime(n).at n=34A287945
• a(n) is the largest prime factor of n*2^n-1.at n=31A367003
• Prime numbersat n=32131750