19531

Properties

Appears in sequences

• Primes of form (p^x - 1)/(p^y - 1), p prime.at n=20A003424
• a(n) = (5^n - 1)/4.at n=7A003463
• Cyclotomic polynomials at x=5.at n=7A019323
• Cyclotomic polynomials at x=-5.at n=14A020504
• Triangle of Gaussian binomial coefficients [ n,k ] for q = 5.at n=29A022169
• Triangle of Gaussian binomial coefficients [ n,k ] for q = 5.at n=34A022169
• Gaussian binomial coefficients [ n,6 ] for q = 5.at n=1A022213
• Prime numbers that are the sum of the divisors of some n.at n=15A023195
• Primes that remain prime through 3 iterations of function f(x) = 3x + 8.at n=16A023279
• Primes that are palindromic in base 5.at n=27A029973
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 94 ones.at n=17A031862
• Number of sublattices of index n in generic 7-dimensional lattice.at n=4A038994
• Largest prime substring in 5^n (0 if none).at n=9A046271
• Numbers that are repdigits in base 5.at n=25A048330
• Primes arising in A048969.at n=43A048977
• Primes followed by a [10,2,10] prime difference pattern of A001223.at n=19A052376
• a(n) = 1111111 in base n.at n=4A053716
• Repunits in different bases: table by antidiagonals of numbers written in base k as a string of n 1's.at n=61A055129
• Primes p with the following property: let d_1, d_2, ... be the distinct digits occurring in the decimal expansion of p. Then for each d_i, dropping all the digits d_i from p produces a prime number. Leading 0's are not allowed.at n=44A057876
• Primes with 4 distinct digits that remain prime (no leading zeros allowed) after deleting all occurrences of its digits d.at n=3A057880