207121

Properties

Appears in sequences

• Fibonacci with priority for primes: a(0)=0, a(1)=1, for n >= 2, a(n) = a(n-1) + a(k), where 0 < k <= n-2 is maximal index such that a(n-1) + a(k) is prime. If there is no such k, then a(n) = a(n-1) + a(n-2).at n=42A216231
• Prime numbers having no additional odd primes in their Collatz (3x+1) trajectory.at n=14A221476
• Prime numbersat n=18557