18947

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of function f(x) = 2x + 3.at n=29A023273
• Smaller term of closest safe prime pairs.at n=16A059323
• Special safe primes (from A005385) such that the next prime is also a safe prime.at n=8A059394
• Smaller of safe prime twins: special safe primes (A005385) p such that the next prime is also the next safe prime and is p+12, i.e., occurs at the closest possible distance, 12.at n=6A059395
• Beginning with 2, primes of the form: least multiple of the previous term followed by a 7. Beginning with 2, a(n) is the least prime of the form k*a(n-1)*10 +7.at n=3A112783
• Primes congruent to 26 mod 53.at n=38A142556
• Primes congruent to 8 mod 59.at n=35A142735
• Primes congruent to 37 mod 61.at n=35A142835
• Primes q (except greater of twin primes) with result 2 under iterations of {r mod (max prime p < r)} starting at r = q.at n=22A175080
• Primes p such that q*p +- (p mod q) are primes, for q=8.at n=24A178416
• Number of (n+1)X(n+1) -11..11 symmetric matrices with every 2X2 subblock having sum zero and one, two or three distinct values.at n=5A211714
• Number of length 7+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.at n=11A248440
• Hankel transform of a(n) is A006720(n+1). Hankel transform of a(n+1) is A006720(n+3).at n=9A254316
• Non-palindromic balanced primes in base 2.at n=32A256081
• Primes prime(k) such that (prime(k)*prime(k+1)+1)/2 is prime.at n=29A266163
• Primes p such that phi(phi(p-1)+1) = phi(phi(p-2)+1).at n=18A271659
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 486", based on the 5-celled von Neumann neighborhood.at n=36A272508
• Primes of the form 25*n^2 + 25*n + 47.at n=21A281437
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 525", based on the 5-celled von Neumann neighborhood.at n=14A282909
• a(1) = 2; a(n + 1) = smallest prime > a(n) such that a(n + 1) - a(n) is the product of 8 primes.at n=17A285693