333667

Properties

Appears in sequences

• Table of prime factors of 10^n - 1 (with multiplicity).at n=39A001270
• Largest prime factor of the "repunit" number 11...1 (cf. A002275).at n=7A003020
• Largest prime factor of the "repunit" number 11...1 (cf. A002275).at n=16A003020
• Largest prime factor of 10^n - 1.at n=8A005422
• Largest prime factor of 10^n - 1.at n=17A005422
• Smallest primitive factor of 10^n - 1. Also smallest prime p such that 1/p has repeating decimal expansion of period n.at n=8A007138
• Primes with unique period length (the periods are given in A007498).at n=4A007615
• Divisors of 999999999.at n=10A027889
• Primes that when squared gives numbers with digits in nondecreasing order.at n=19A028865
• Primes p such that 666p is palindromic.at n=13A030095
• Prime 3 followed by unique period primes (the period r of 1/p is not shared with any other prime) of the form A019328(r)/gcd(A019328(r),r) in order (periods r are given in A051627).at n=6A040017
• Triangle of prime numbers in which n-th row lists all primes p such that 1/p has decimal period n, n >= 1.at n=12A046107
• Greatest prime number p(n) with decimal fraction period of length n.at n=8A061075
• Prime divisors of solutions to 10^n == 1 (mod n).at n=21A066364
• a(n) = (10^(2*n) + 10^n + 1)/3.at n=3A074992
• a(n) is the largest prime divisor of the number A173426(n) = concatenate(1,2,...,n-1,n,n-1,...,2,1); a(1) = 1.at n=8A075024
• Greatest prime factor of n-th cyclic number.at n=2A087020
• A nonsense sequence (not well-defined).at n=27A089174
• Irregular triangle read by rows in which row n lists prime factors (with multiplicity) of the repunit (10^n - 1)/9 (A002275(n)).at n=22A102380
• a(n) is the smallest prime p such that the multiplicative order of 10 modulo p is 3^n.at n=2A122787