19889

Properties

Appears in sequences

• Numbers k such that (6^k - 1)/5 is prime.at n=12A004062
• Primes that remain prime through 3 iterations of the function f(x) = 2*x + 1.at n=17A023272
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 16.at n=13A031604
• Dirichlet convolution of 3^(n-1) with primes (with 1).at n=9A034752
• Values of A (the short leg) of a Pythagorean triangle with A and C (the hypotenuse) both prime and part of a twin prime.at n=34A051642
• Primes starting a Cunningham chain of the first kind of length 4.at n=12A059763
• Numbers n such that n, 2n+1, 3n+2, 4n+3 are primes.at n=9A067257
• Primes related to the nondecreasing subsequence of A007605 (sums of digits of primes).at n=40A067954
• Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.at n=31A075585
• Upper prime of a difference of 22 between consecutive primes.at n=36A098976
• Primes with digit sum = 35.at n=2A106770
• Smallest primes starting a complete three iterations Cunningham chain of the first or second kind.at n=18A110025
• Prime numbers p such that p^3 - (p+1)^2 and p^3 + (p+1)^2 are both primes.at n=20A137476
• Primes of the form n^2+8.at n=14A138338
• Primes congruent to 6 mod 59.at n=39A142733
• Primes congruent to 3 mod 61.at n=39A142801
• Numbers n such that n-+1 are divisible by exactly 6 primes, counted with multiplicity.at n=22A157486
• E.g.f. A(x) satisfies A(x) = exp( x*A(2*x)^2 ).at n=4A168600
• List of primes p1 such that (p1,p2) are twin primes where both 2*p1+p2 and p1+2*p2 are primes.at n=11A174920
• Primes of form a^2+b^2 such that a^4+b^4 and a^8+b^8 are primes.at n=14A182313