A069109 Primes of the form F(k)-k where F(k) is the k-th Fibonacci number.

2, 13, 971, 121367, 317783, 3416454622906631, 3807901929474025356630904133903, 757791618667731139247631372099907

Offset: 1

Author

Benoit Cloitre, Apr 06 2002

Keywords

• nonn

Comments

a(9) is a 169-digit certified prime (Primo). - Rick L. Shepherd, Apr 26 2002

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..13

Crossrefs

Cf. A000045, A065220, A270821.

Programs

Mathematica

Select[Table[Fibonacci[k] - k, {k, 1, 160}], PrimeQ] (* Amiram Eldar, Jun 04 2022 *)

PARI

for(n=1, 4036, if(ispseudoprime(t=fibonacci(n)-n), print1(t", "))); \\ Charles R Greathouse IV, Feb 17 2011

Formula

A065220 INTERSECT A000040. - R. J. Mathar, Apr 24 2017

a(n) = A065220(A270821(n)). - Amiram Eldar, Jun 04 2022