cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

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

Original entry on oeis.org

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

Views

Author

Alexander Adamchuk, Sep 18 2006

Keywords

Comments

The corresponding primes are {2,5,89,1597,99194853094755497,...}.
Numbers k such that A093308(k) is prime.
A277575(n) = prime(a(n)) is a prime in A119984.

Crossrefs

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

Formula

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

A277284 Prime-indexed primes p such that Fibonacci(p) is prime.

Original entry on oeis.org

3, 5, 11, 17, 83, 431, 509, 130021, 148091, 433781
Offset: 1

Views

Author

Bobby Jacobs, Oct 21 2016

Keywords

Comments

Intersection of A006450 and A083668. - Michel Marcus, Oct 21 2016

Examples

			17 = A000040(7), with 7 itself being a prime, and A000045(17) = 1597, a prime, thus 17 is included in this sequence.

Crossrefs

Cf. A000040, A000045, A006450, A083668, A122534, A277575.

Programs

  • Mathematica
    Select[Prime[Prime[Range[37000]]],PrimeQ[Fibonacci[#]]&] (* Harvey P. Dale, Sep 12 2019 *)
  • PARI
    isok(p) = isprime(p) && isprime(primepi(p)) && isprime(fibonacci(p)); \\ Michel Marcus, Oct 21 2016

Formula

a(n) = prime(A277575(n)).
a(n) = prime(prime(A122534(n))).
Showing 1-2 of 2 results.

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