18973

Properties

Appears in sequences

• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 72 ones.at n=34A031840
• Expansion of (1-x+x^2)/((x^2+x+1)*(x^2+5*x+1)).at n=6A110310
• Mother primes of order 8.at n=33A136067
• Primes congruent to 34 mod 59.at n=35A142761
• Primes congruent to 2 mod 61.at n=34A142800
• Primes of the form 20*k^2 + 32*k + 13.at n=15A154414
• Primes that divide every circular permutation of the digits of at least one number of the form 123...(k-1)(k) (see A007908), where k is 3 digits long (that is, for some k in the range 99 < k < 1000).at n=26A180346
• Smallest of three consecutive primes whose sum is a triangular number.at n=8A226148
• List of prime factors of 10^(10^(10^100)) - 10.at n=35A227246
• Primes p such that p - ssd(p) is the square of a prime, where ssd(k) is the sum of the squared decimal digits of k.at n=6A227785
• Primitive prime factors of the cyclotomic polynomial sequence Phi(9,k) in the order in which they occur.at n=14A256144
• Primes p such that 2*p + 79 is a square.at n=7A269790
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 339", based on the 5-celled von Neumann neighborhood.at n=30A271291
• a(n) = (conjectured) smallest positive integer k which is neither of the form p + n^x nor of the form p - n^x with x >= 0 and p prime, where gcd(k, n) = 1 and gcd(k^2-1, n-1) = 1.at n=28A283619
• Triangle read by rows: T(n,k) is the number of rooted ordered trees with node weights summing to n, where the root has weight 0, all internal nodes have weight 1, and leaf nodes have weights in {1,...,k}.at n=52A384685
• Prime numbersat n=2157