206923

Properties

Appears in sequences

• Prime numbers having no additional odd primes in their Collatz (3x+1) trajectory.at n=13A221476
• a(n) is the number of permutations of length n that avoid the pattern 321 and the mesh pattern (12, 275) or the same sequence for the mesh patterns (12, 281), (12, 305), (12, 401).at n=12A289606
• Prime numbersat n=18542