206369

Properties

Appears in sequences

• Primes that remain prime through 4 iterations of function f(x) = 2x + 1.at n=13A023302
• Initial (unsafe) primes of Cunningham chains of first type with length exactly 5. Primes in A059453 that survive as primes just four "2p+1 iterations", forming chains of exactly 5 terms.at n=8A059764
• Primes p such that 2p+1, 4p+3, 6p+5, 8p+7 are all primes.at n=11A107021
• Smallest primes starting a complete four iterations Cunningham chain of the first or second kind.at n=18A110027
• Prime numbersat n=18500