117239

Properties

Appears in sequences

• Wagstaff numbers: numbers k such that (2^k + 1)/3 is prime.at n=32A000978
• Numbers k such that 2^k + 1 is the product of two distinct primes.at n=50A073936
• Numbers k such that 2^k + 1 is a semiprime.at n=51A092559
• Indices of prime Jacobsthal numbers.at n=33A107036
• Primes of the form 22*(n^2)+1.at n=29A117049
• Primes of the form 22*(n^2)+1 for which the sum of the digits is also of the form 22*(n^2)+1.at n=2A117050
• List of strictly non-palindromic twin primes {p, p+2}.at n=34A138329
• Lesser of twin primes such that both twin primes have no bases b, 1 < b < p-1, in which p is a palindrome.at n=17A138348
• Primes p such that p-+1, p-+3, p-+5 are not squarefree.at n=23A155145
• Numbers n such that (2^n+1)/3 is prime, but cannot be written in the form a^2 + 3*b^2.at n=17A216551
• a(n) = Sum_{k=0..3} binomial(6,k)*binomial(n,k).at n=33A247608
• Numbers k such that (2^k + 1)/(2 - (-1)^k) is a prime.at n=37A280083
• a(n) = prime that is eventually reached when x -> sigma(x)-1 is repeatedly applied to the product of the first n primes, or -1 if no prime is ever reached.at n=5A291301
• Wagstaff numbers that are of the form 4*k + 3.at n=20A361562
• Prime numbersat n=11065