A122534 Numbers n such that Fibonacci(prime(prime(n))) is prime.

1, 2, 3, 4, 9, 23, 25, 1456, 1616, 3865

Offset

1,2

Comments

a(n) are perfect squares for n = {1,4,5,7,...}. a(8) and a(9) are divisible by 16 = 2^4. Corresponding Fibonacci primes Fibonacci[Prime[Prime[a(n)]]] = {2,5,89,1597,99194853094755497,...} that is a subset of A093308[n]. Corresponding prime indices of Fibonacci primes Prime[Prime[a(n)]] = (3,5,11,17,83,431,509,130021,148091,433781,...}. Corresponding prime indices Prime[a(n)] = {2,3,5,7,23,83,97,12161,13681,36467,...} that are the primes in A119984[n] Numbers n such that Fibonacci[Prime[n]] is prime.

Links

Table of n, a(n) for n=1..10.

Formula

a(n) = PrimePi(A277575(n)) = PrimePi(PrimePi(A277284(n))). - Bobby Jacobs, Oct 26 2016

Crossrefs

Cf. A000040, A000045, A119984, A083668, A093308, A075737, A001605, A006450, A005478, A030426, A277284, A277575.

Sequence in context: A361326 A280016 A089243 * A101135 A280054 A088220

Adjacent sequences: A122531 A122532 A122533 * A122535 A122536 A122537

Keyword

hard,more,nonn

Author

Alexander Adamchuk, Sep 18 2006

Status

approved