18217

Properties

Appears in sequences

• a(n) = [ a(n-1)/a(1) + a(n-2)/a(2) + ... + a(1)/a(n-1) ], for n >= 3.at n=21A022863
• Primes of the form k^2 - 8.at n=31A028886
• Primes p such that (p+1)/2 and (p+2)/3 are also primes.at n=37A036570
• Second member of a sexy prime quadruple: value of p+6 such that p, p+6, p+12 and p+18 are all prime.at n=33A046122
• Second term of balanced prime quartets: p(m)-p(m-1) = p(m+1)-p(m) = p(m+2)-p(m+1).at n=13A054801
• a(n) = 2*prime(n)^2 - prime(n+1)^2.at n=32A064051
• Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d = 2, 4 or 6) and forming d-pattern = [6, 6, 4]; short d-string notation of pattern = [664].at n=13A078858
• Primes of the form (prime(k-1)+1)*(prime(k+1)-1) + 1, k>1.at n=10A087106
• Primes p such that p - 6^2, p - 6, p + 6 and p + 6^2 are also primes.at n=35A141279
• Primes congruent to 38 mod 53.at n=39A142568
• Primes congruent to 45 mod 59.at n=38A142772
• Primes congruent to 39 mod 61.at n=30A142837
• Number of nondecreasing integer sequences of length 25 with sum zero and sum of absolute values 2n.at n=13A158159
• Primes p such that (p reversed)+ 8 is a square.at n=39A167470
• Numbers k such that k and k+6 are both balanced primes.at n=13A173892
• Primes p that p//13 and p//31 are consecutive primes.at n=27A176601
• Consider two consecutive primes {p,q} such that {P=2p-q,Q=2q-p} are both prime. Sequence gives lesser primes p.at n=39A186169
• Primes of the form 7n^2 + 10.at n=13A201610
• Primes of the form 9n^2 - 8.at n=10A201961
• Number of n X 1 0..2 arrays with every element value z a city block distance of exactly z from another element value z.at n=13A209469