18731

Properties

Appears in sequences

• Number of chains in power set of n-set.at n=6A007047
• Numbers whose base-5 representation contains exactly three 1's and three 4's.at n=29A045262
• Doubly balanced primes: primes which are averages of both their immediate and their second neighbors.at n=0A051795
• Primes p such that p-12, p and p+12 are consecutive primes.at n=15A053072
• Central prime p in the smallest (2n+1)-tuple of consecutive primes that are symmetric with respect to p.at n=1A055380
• Basis for code in A075931.at n=6A075932
• Duplicate of A051795.at n=0A081416
• Numbers k such that 5^k + 2 is a prime.at n=8A087885
• Balanced primes of order seven.at n=17A096699
• Balanced primes (A090403) of index 3.at n=14A096707
• Numbers p such that p = (prime(n)+ prime(n+2))/2 is prime for prime indices n=2, 3, 5...at n=21A098038
• Primes congruent to 22 mod 53.at n=38A142552
• Primes congruent to 28 mod 59.at n=34A142755
• Primes congruent to 4 mod 61.at n=38A142802
• Primes which are the sum of 6 consecutive triangular numbers A000217.at n=10A159071
• Mountain emirps.at n=20A182721
• Prime numbers > 10000 such that all the substrings of length >= 4 are primes (substrings with leading '0' are considered to be nonprime).at n=29A211686
• Larger of pairs of emirps (A006567) whose difference with the (smaller) reversal is a triangular number (A000217).at n=17A217286
• Primes p such that p1 = ceiling(p/2) + p is prime and p2 = floor(p1/2) + p is prime.at n=39A242366
• P(n,k) is an array read by rows, with n > 0 and k=1..5, where row n gives the chain of 5 consecutive primes {p(i), p(i+1), p(i+2), p(i+3), p(i+4)} having the symmetrical property p(i) + p(i+4) = p(i+1) + p(i+3) = 2*p(i+2) for some index i.at n=2A267028