305175781

Properties

Appears in sequences

• a(n) = (5^n - 1)/4.at n=13A003463
• Cyclotomic polynomials at x=5.at n=13A019323
• Gaussian binomial coefficients [ n,12 ] for q = 5.at n=1A022219
• Largest prime substring in 5^n (0 if none).at n=15A046271
• Prime repunits in ascending prime bases (written in decimal).at n=2A048756
• a(n) = Sum_{j=0..12} n^j.at n=5A060887
• Zsigmondy numbers for a = 5, b = 1: Zs(n, 5, 1) is the greatest divisor of 5^n - 1^n (A024049) that is relatively prime to 5^m - 1^m for all positive integers m < n.at n=12A064081
• Primes of the form sigma(m^2) where m is a composite number ordered by values m.at n=20A065403
• Largest prime factor of 5^n - 1.at n=12A074479
• Largest prime factor of 5^n - 1.at n=25A074479
• Primes of the form (5^k-1)/4.at n=3A086122
• Primes of the form (5^k-1)/4 or (5^k+3)/4.at n=9A088554
• a(n) = (Sum_{i=0..n} 5^i) + 1 - (Sum_{i=0..n} 5^i) mod 2.at n=12A102239
• a(n) is the least prime such that the multiplicative order of 5 mod a(n) equals n.at n=12A143665
• a(n) = (5^n - 1)/(2^(3 - (n mod 2))).at n=13A152417
• a(n) = Sum_{d|n} Moebius(n/d)*d^(b-1)/phi(n) for b = 14.at n=4A161010
• Legal generalized repunit prime numbers.at n=24A179625
• Minimal order of degree-n irreducible polynomials over GF(5).at n=12A218357
• Expansion of x*(1+5*x-5*x^3)/(1-6*x^2+5*x^4).at n=24A249222
• Primes of the form Phi(k, -5), where Phi is the cyclotomic polynomial.at n=6A291998