178481

Properties

Appears in sequences

• Table T(n,k) in which n-th row lists prime factors of 2^n - 1 (n >= 2), with repetition.at n=58A001265
• a(n) = largest noncomposite factor of 2^(2n+1) - 1.at n=11A002588
• Largest prime factor of n-th Mersenne number (A001348(n)).at n=8A003260
• Divisors of 2^46 - 1.at n=4A003551
• Largest prime factor of 2^n - 1.at n=21A005420
• Numbers n such that game of n X n Button Madness need have no solution; this lists only the primitive elements of the set.at n=20A007802
• Table T(n,k) in which n-th row lists prime factors of 2^n - 1 (n >= 2), without repetition.at n=54A060443
• For p = prime(n), a(n) is the smallest 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=13A085012
• Second prime factor, if it exists, of Mersenne numbers.at n=1A089158
• Triangle read by rows formed by the prime factors of Mersenne number 2^prime(n) - 1, n >= 1.at n=10A089162
• Largest primitive prime factor of 2^n-1, or a(n) = 1 if no such prime exists.at n=22A097406
• A006530(x)=2 is a local minimum if x=2^n. Running downward with argument x started at 2^n, the largest prime divisor should increase. The value of first peak is a(n).at n=22A102644
• 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=22A108974
• List of primitive prime divisors of the numbers (4^n-1)/3 (A002450) in their order of occurrence.at n=36A129735
• Number of distinct self-dual normal bases for GF(2^n) over GF(2).at n=46A135488
• Largest prime factor of composite Mersenne numbers.at n=1A136031
• Numbers 2*k+1 for which numbers A006694(k) are record values for A006694.at n=39A139208
• 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=15A143027
• a(n) is the largest proper divisor of the Mersenne composite A065341(n).at n=1A145097
• Duplicate of A136031.at n=1A145098