19961

Properties

Appears in sequences

• Primes that remain prime through 4 iterations of function f(x) = 9x + 2.at n=15A023324
• 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 14.at n=11A031602
• 24 'Reverse and Add' steps are needed to reach a palindrome.at n=5A065318
• Beginning with 2, least prime not occurring earlier such that the concatenation of first n terms has the least prime factor prime(n).at n=34A100759
• Least prime p of a quartet of 4 distinct primes {p, p+2, q, q+2} such that each digit of q is the same as the corresponding digit of p except that each 6 in p corresponds to a 9 in q and vice versa.at n=5A122712
• Primes p2 such that p1^2 + p2^3 is an average of twin primes and p1 < p2 are consecutive primes.at n=20A138716
• Primes congruent to 14 mod 61.at n=35A142812
• Primes which become emirps when rotated by 180 degrees on a digital clock display.at n=16A145750
• Primes p such that p^3 - 12 and p^3 + 12 are also primes.at n=25A153322
• Prime numbers q of primitive Pythagorean triangles such that perimeters are averages of twin prime pairs, p+1=q(prime), a=q^2-p^2, c=q^2+p^2, b=2*p*q, ar=a*b/2; s=a+b+c, s-+1 are primes.at n=31A155187
• Primes that start a run of at least seven consecutive primes, where between successive primes exactly one digit changes and the resulting digits may be permuted.at n=22A157717
• Primes that become squares when prefixed with a 2.at n=14A167735
• G.f.: (1+x)^(2*g)*(1+x^3)^(3*g)/((1-x^2)*(1-x^4))-x^(2*g)*(1+x)^4/((1-x^2)*(1-x^4)) for g=3.at n=18A199629
• Primes p such that p+2 and q are primes, where q is concatenation of binary representations of p and p+2: q = p * 2^L + p+2, where L is the length of binary representation of p+2: L=A070939(p+2).at n=23A232238
• Seventh prime p such that (p+n)^2+n is prime but (p+j)^2+j is not prime for all 0<j<n.at n=18A238679
• Prime numbers p such that p^3 is an interprime = average of two successive primes.at n=30A248799
• Lesser of twin primes such that sum of twin prime pair is the sum of 2 nonzero squares.at n=36A270245
• Initial member of 6 consecutive primes a, b, c, d, e, f such that both (f + a)/(d - c) and (e + b)/(d - c) are prime.at n=11A293619
• SanD-68 primes p: such that p+d is also prime and sum of digits A007953(p(p+d)) = d, with d = 68.at n=0A307474
• Smallest SanD-d prime p (such that p + d is also prime and digit sum A007953(p(p+d)) = d) with d = 14 + n*18, n >= 0, resp. d = 5 for n = -1.at n=4A307480