12207031

Properties

Appears in sequences

• a(n) = (5^n - 1)/4.at n=11A003463
• Cyclotomic polynomials at x=5.at n=11A019323
• Cyclotomic polynomials at x=-5.at n=22A020504
• Gaussian binomial coefficients [ n,10 ] for q = 5.at n=1A022217
• Sublattices of index n in generic 11-dimensional lattice.at n=4A038998
• Largest prime substring in 5^n (0 if none).at n=13A046271
• a(n) = Sum_{j=0..10} n^j.at n=5A060885
• 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=10A064081
• Primes of the form sigma(m^2) where m is a composite number ordered by values m.at n=15A065403
• Z(S_m; sigma[1](n), sigma[2](n),..., sigma[m](n)) where Z(S_m; x_1,x_2,...,x_m) is the cycle index of the symmetric group S_m and sigma[k](n) is the sum of k-th powers of divisors of n; m=10.at n=4A068027
• Value of prime(n)-th cyclotomic polynomial at n.at n=4A070521
• Largest prime factor of 5^n - 1.at n=10A074479
• Largest prime factor of 5^n - 1.at n=21A074479
• Numbers of the form (5^{mr}-1)/(5^r-1) for positive integers m, r.at n=27A076284
• Let p be the n-th prime; Cp(x) be the p-th cyclotomic polynomial (x^p-1)/(x-1); a(n) is the first prime Cp(x) after Cp(1).at n=4A084732
• Let Cn(x) be the n-th cyclotomic polynomial; a(n) is the first prime Cn(x) after Cn(1).at n=10A085399
• Primes of the form (5^k-1)/4.at n=2A086122
• Primes of the form (5^k-1)/4 or (5^k+3)/4.at n=7A088554
• a(n) = (Sum_{i=0..n} 5^i) + 1 - (Sum_{i=0..n} 5^i) mod 2.at n=10A102239
• Smallest prime of the form (q^p-1)/(q-1), where p = prime(n) and q is also prime (q = A123487(n)).at n=4A123488