164511353

Properties

Appears in sequences

• a(n) = largest noncomposite factor of 2^(2n+1) - 1.at n=20A002588
• Largest prime factor of n-th Mersenne number (A001348(n)).at n=12A003260
• Largest prime factor of 2^n - 1.at n=39A005420
• Second prime factor, if it exists, of Mersenne numbers.at n=4A089158
• Triangle read by rows formed by the prime factors of Mersenne number 2^prime(n) - 1, n >= 1.at n=18A089162
• Largest primitive prime factor of 2^n-1, or a(n) = 1 if no such prime exists.at n=40A097406
• Largest prime factor of composite Mersenne numbers.at n=4A136031
• a(n) is the largest proper divisor of the Mersenne composite A065341(n).at n=4A145097
• Duplicate of A136031.at n=4A145098
• Irregular triangle in which row n has all primes q such that prime(n)*q is a base-2 Fermat pseudoprime.at n=39A180471
• Primes p such that (p-1)/ord(2,p) > (q-1)/ord(2,q) for odd primes q < p.at n=31A226216
• Prime factors of 2^A054723(n)-1, ordered by increasing n, then by increasing size of the factors.at n=10A244453
• 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=12A247229
• Prime numbersat n=9213126