30713

Properties

Appears in sequences

• Primes p whose period of reciprocal equals (p-1)/11.at n=11A056216
• Numbers n such that (19^n + 1)/20 is a prime.at n=7A057185
• Numbers k such that k + (largest digit of k)! is a palindromic prime.at n=15A095920
• Duplicate of A056216.at n=11A098678
• Smallest prime p such that the sum of it and the following prime has n prime factors including multiplicity, or 0 if no such prime exists.at n=13A105418
• Positive integers of the form (18*m^2+1)/11.at n=24A113338
• Prime numbers p such that p^3 - (p+1)^2 and p^3 + (p+1)^2 are both primes.at n=31A137476
• Noncomposite numbers in the eastern ray of the Ulam spiral as oriented on the March 1964 cover of Scientific American.at n=25A168022
• Numbers n such that Sum(1/d*_n)>Sum(1/d*_m) for all m<n, where d*_n and d*_m are the anti-divisors of n and m.at n=17A192294
• Prime numbers whose central digit equals the sum of the other digits.at n=23A235119
• a(0) = 16, after which, if a(n-1) = product_{k >= 1} (p_k)^(c_k), then a(n) = (1/2) * (1 + product_{k >= 1} (p_{k+1})^(c_k)), where p_k indicates the k-th prime, A000040(k).at n=19A246344
• Three-column array read by rows: the first row consists of the first two primes, p = 2 and q = 3, and their sum s = p + q = 5; afterwards the (n+1)-st row consists of the smallest pair of consecutive primes whose sum is a multiple of the sum in the n-th row followed by their sum.at n=27A284669
• Number of nX4 0..1 arrays with every element unequal to 0, 1, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=14A318346
• a(n) is the least prime p such that the 2-adic valuation of q^2-p^2 is n, where q is the next prime after p, or 0 if there is no such p.at n=13A340116
• a(n) is the least prime p such that the 2-adic valuation of p+q is n, where q is the next prime after p, or 0 if there is no such p.at n=12A340117
• Integers k such that A005245(m*k) < A005245(k) for some m.at n=12A380464
• Prime numbersat n=3314