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A178576 Primes that are the sum of two Fibonacci numbers. 4

%I #27 May 13 2013 01:54:11

%S 2,3,5,7,11,13,23,29,37,47,89,97,149,157,199,233,241,379,521,613,631,

%T 1021,1597,1741,2207,3571,9349,10949,11933,17713,28657,46381,46457,

%U 46601,50549,75169,196439,203183,214129,514229,560597,832129,2178343

%N Primes that are the sum of two Fibonacci numbers.

%C The corresponding prime indices are in A178971.

%H Charles R Greathouse IV, <a href="/A178576/b178576.txt">Table of n, a(n) for n = 1..5624</a>

%e Prime 613 can be expressed as 3+610 = Fibonacci(4)+Fibonacci(15), therefore 613 is in the sequence.

%t f=Fibonacci[Range[33]]; Select[Union[Flatten[Outer[Plus, f, f]]], PrimeQ]

%o (PARI) list(lim)={

%o my(v,u=List(),t);

%o v=vector(log(lim*sqrt(5))\log((1+sqrt(5))/2)+1,n,fibonacci(n));

%o for(i=1,#v,for(j=i+1,#v,

%o t = v[i] + v[j];

%o if(t > lim, break);

%o if(ispseudoprime(t),listput(u, t))

%o ));

%o vecsort(Vec(u),,8)

%o }; \\ _Charles R Greathouse IV_, Jul 23 2012

%Y Cf. A000040, A000045, A178971. Subsequence of A059389.

%K nonn

%O 1,1

%A _Carmine Suriano_, Jan 12 2011

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Last modified March 28 15:28 EDT 2024. Contains 371254 sequences. (Running on oeis4.)