27689

Properties

Appears in sequences

• a(n) = (5*n + 1)^2 + 4*n + 1.at n=33A007533
• Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 3.at n=22A050665
• 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=[2,6,4]; short d-string notation of pattern = [264].at n=27A078848
• Lower of twin primes (p,p+2) such that (p*(p+2))^2 + p^2 - (p+2)^2 and (p*(p+2))^2 - p^2 + (p+2)^2 are both prime.at n=3A079812
• Smallest d such that real quadratic field with discriminant d has class number n.at n=24A081364
• Prime(prime(n)) when prime(prime(n)) and n are twin primes.at n=20A087394
• Smallest member of a pair of consecutive twin prime pairs that have three primes between them.at n=32A089635
• Primes with digit sum = 32.at n=21A106768
• Primes of the form i*prime(i) + (i+1)*prime(i+1).at n=22A119487
• Number of n X n binary arrays with all ones connected only in a 01000-11111-00010 pattern in any orientation.at n=8A147011
• Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 01000-11111-00010 pattern in any orientation.at n=18A147013
• Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 01000-11111-00010 pattern in any orientation.at n=19A147013
• List of primes of the form 25n^2-36n+13 with n>=0.at n=10A154354
• a(n) = 25*n^2 - 36*n + 13.at n=34A154355
• Lesser of twin primes p1 such that p1+(p2^2-p1^2) and p2+(p2^2-p1^2) are prime numbers.at n=35A174922
• Smallest prime that can be expressed as the sum of n distinct positive squares with the largest square as small as possible.at n=41A224498
• 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=38A232238
• Lesser of twin-bin primes: primes p such that p+2, x and y are primes, where x is concatenation of binary representations of p and p+2, and y is concatenation of binary representations of p+2 and p: x = p * 2^A070939(p+2) + p+2, y = (p+2) * 2^A070939(p) + p.at n=4A232239
• Primes p such that p+2, p+8, and p+12 are all prime.at n=35A233540
• Near-Wilson primes (p = prime(n) satisfying (p-1)! == -1-A250406(n)*p (mod p^2)) with A250406(n) < 10.at n=19A250407