51971

Properties

Appears in sequences

• Primes with all odd digits such that the next three primes also contain all odd digits.at n=32A068831
• Lower of twin primes (p,p+2) such that (p*(p+2))^2 + p^2 - (p+2)^2 and (p*(p+2))^2 - p^2 + (p+2)^2 are both prime.at n=7A079812
• A triangle sequence based on a prime root product using a primorial function: f(n)=primorial(n); p(x,n)=If[n == 0, 1, f(n)*(x + 1/f(n))*Product[x + Prime[i], {i, 1, n - 1}]]; t(n,m)=coefficients(p(x,n)).at n=17A142583
• Primes of the form n^2 - 13.at n=22A154648
• a(1) = greatest k such that H(k) - H(2) < 1/1 + 1/2; a(2) = greatest k such that H(k) - H(a(1)) < H(a(1)) - H(2); and for n>2, a(n) = greatest k such that H(k) - H(a(n-1)) < H(a(n-1)) - H(a(n-2)), where H = harmonic number.at n=6A227728
• a(n) is the first prime p such that the concatenations of n consecutive primes, starting with p, in both forward and backward directions, are prime.at n=24A384958
• Primes k such that the concatenation of (b, k, b) and (k, b, k) are both prime, where b is the binary representation of k.at n=19A389801
• Prime numbersat n=5316