login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A135724
Fibonacci numbers whose indices are prime Fibonacci numbers: a(n) = Fibonacci(A001605(n)).
1
1, 2, 5, 233, 1779979416004714189, 2211236406303914545699412969744873993387956988653
OFFSET
1,2
COMMENTS
The only known prime numbers in this sequence are 2, 5 and 233.
The next term (a(6)) has 334 digits. - Harvey P. Dale, Apr 28 2023
LINKS
MATHEMATICA
a = {}; b = {}; Do[If[PrimeQ[c = Fibonacci[n]], w = Fibonacci[Fibonacci[n]]; AppendTo[a, w]; AppendTo[b, n]], {n, 1, 31}]; a
Fibonacci[#]&/@Select[Fibonacci[Range[20]], PrimeQ] (* Harvey P. Dale, Apr 28 2023 *)
KEYWORD
nonn
AUTHOR
Artur Jasinski, Nov 26 2007
EXTENSIONS
Corrected by Harvey P. Dale, Apr 28 2023
STATUS
approved