26407

Properties

Appears in sequences

• Primes of the form p^k - p + 1 for prime p.at n=19A034915
• Primes p such that x^27 = 2 has no solution mod p, but x^9 = 2 has a solution mod p.at n=11A059354
• Primes p such that x^54 = 2 has no solution mod p, but x^18 = 2 has a solution mod p.at n=5A059666
• Primes p such that p-1 divides 2^p-2.at n=21A069051
• Primes p such that x^9 = 2 has a solution mod p, but x^(9^2) = 2 has no solution mod p.at n=12A070185
• Primes of the form p^2 - p + 1 where p is prime.at n=8A074268
• First prime after phi(prime(n)^2).at n=37A079477
• Primes of the form p^k - p^(k-1) + 1 for some prime p and integer k > 1.at n=19A087126
• The number of n-almost primes less than or equal to e^n, starting with a(0)=1.at n=28A116432
• p^2-p+1 central polygonal numbers with prime indices A002061(prime(n)).at n=37A119959
• Primes of the form p^e - p^(e-1) + p^(e-2) - ... + (-1)^e, where p is prime.at n=17A127727
• Noncomposite numbers in the southwestern ray of the Ulam spiral as oriented on the March 1964 cover of Scientific American.at n=19A168026
• Primes of the form n^2 + n + 1 where n is nonprime.at n=37A185632
• Primes p such that p^2 divides 2^(2^(p-1)-1) - 1.at n=30A188465
• Number of nX1 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to one or two horizontal or vertical neighbors.at n=23A199034
• Eighth 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=16A238680
• Number of compositions of n such that the first part is 1 and the second differences of the parts are in {-3,...,3}.at n=19A239553
• Primes of form x^2 - phi(x) in increasing order.at n=14A258435
• Primes in A258774.at n=27A258776
• Least prime p such that 2p*n+1 = prime(q*n) for some prime q.at n=43A260208