A281087
Numbers k such that Fibonacci(k) and Fibonacci(k+2) are both prime.
Original entry on oeis.org
3, 5, 11, 431, 569
Offset: 1
11 is in the sequence because Fibonacci(11) = 89 and Fibonacci(13) = 233 are both prime.
First differs from
A101315 at a(5).
-
Select[Range[600],PrimeQ[Fibonacci[#]] && PrimeQ[Fibonacci[#+2]] &] (* Stefano Spezia, Nov 15 2024 *)
SequencePosition[Table[If[PrimeQ[Fibonacci[n]],1,0],{n,600}],{1,,1}][[;;,1]] (* _Harvey P. Dale, Jan 30 2025 *)
A279795
Numbers n such that F(n) and F(n-2) are both prime where F(n) = A000045(n).
Original entry on oeis.org
5, 7, 13, 433, 571
Offset: 1
13 is a term because Fibonacci(13) = 233 and Fibonacci(11) = 89 are both prime.
-
Select[Range[10^4], Times @@ Boole@ Map[PrimeQ@ Fibonacci@ # &, {#, # - 2}] > 0 &] (* Michael De Vlieger, Jan 21 2017 *)
Flatten[Position[Partition[Fibonacci[Range[580]],3,1],?(AllTrue[ {#[[1]],#[[3]]},PrimeQ]&),1,Heads->False]]+2 (* _Harvey P. Dale, Oct 01 2021 *)
-
isok(n) = isprime(fibonacci(n)) && isprime(fibonacci(n-2)); \\ Michel Marcus, Jan 14 2017
A297624
Numbers k such that Fibonacci(2*k+1) and Fibonacci(2*k-1) are prime.
Original entry on oeis.org
2, 3, 6, 216, 285
Offset: 1
2 is in the sequence because F(3)=2 and F(5)=5 are prime.
6 is in the sequence because F(11)=89 and F(13)=233 are prime.
-
o := [];; for k in [1..500] do if IsPrime(Fibonacci(2*k+1)) and IsPrime(Fibonacci(2*k-1)) then Add(o,k); fi; od; A297624 := o; # Muniru A Asiru, Jan 25 2018
-
[n: n in [0..700] | IsPrime(Fibonacci(2*n+1)) and IsPrime(Fibonacci(2*n-1))];
-
with(combinat, fibonacci): select(k -> isprime(fibonacci(2*k+1)) and isprime(fibonacci(2*k-1)), [$1..500]); # Muniru A Asiru, Jan 25 2018
-
Select[Range[0, 3000], PrimeQ[Fibonacci[2 # + 1]] && PrimeQ[Fibonacci[2 # - 1]] &]
-
isok(n) = isprime(fibonacci(2*n-1)) && isprime(fibonacci(2*n+1)); \\ Michel Marcus, Jan 08 2018
-
from sympy import isprime
A297624_list, k, a, b, c, aflag = [], 1, 1, 1, 2, False
while k < 1000:
cflag = isprime(c)
if aflag and cflag:
A297624_list.append(k)
k, a, b, c, aflag = k + 1, c, b + c, b + 2*c, cflag # Chai Wah Wu, Jan 23 2018
Showing 1-3 of 3 results.
Comments