A319393 Indices of triple prime Fibonacci numbers: numbers k such that (1) Fibonacci(k) is prime, (2) k is prime, and (3) the sum of the digits of Fibonacci(k) is prime.
3, 5, 11, 29, 43, 47, 449, 104911
Offset: 1
Examples
29 is a term of the sequence, since 29 is prime, Fibonacci(29) = A000045(29) = 514229 is prime and the digit sum of 514229 = A007953(514229) = 23 is also prime. - _Felix Fröhlich_, Sep 18 2018
Programs
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Mathematica
Select[Prime[Range[100]],AllTrue[{Fibonacci[#],Total[ IntegerDigits[ Fibonacci[ #]]]}, PrimeQ] &] (* The program uses the AllTrue function from Mathematica version 10 *) -
PARI
is(n) = if(!ispseudoprime(n), return(0), my(f=fibonacci(n)); if(!ispseudoprime(sumdigits(f)), return(0), if(ispseudoprime(f), return(1), return(0)))) \\ Felix Fröhlich, Sep 18 2018
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