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%I #30 Feb 17 2023 01:59:16
%S 1,1,2,3,5,2,13,3,2,5,89,2,233,13,2,3,1597,2,37,3,2,89,28657,2,5,233,
%T 2,3,514229,2,557,3,2,1597,5,2,73,37,2,3,2789,2,433494437,3,2,139,
%U 2971215073,2,13,5,2,3,953,2,5,3,2,59,353,2,4513,557,2,3,5,2,269,3,2,5
%N a(1) = a(2) = 1; for n >2, a(n) = smallest prime factor of n-th Fibonacci number.
%H Tyler Busby, <a href="/A060383/b060383.txt">Table of n, a(n) for n = 1..1452</a> (terms 1..1000 from Alois P. Heinz, derived from Kelly's data, terms 1001..1408 from Amiram Eldar)
%H Blair Kelly, <a href="http://mersennus.net/fibonacci//">Fibonacci and Lucas Factorizations</a>
%F a(n) = A020639(A000045(n)). - _Michel Marcus_, Nov 15 2014
%e For n=82: F(82) = 2789*59369*370248451, so a(82)=2789.
%t f[n_] := (FactorInteger@ Fibonacci@ n)[[1,1]]; Array[f, 70] (* _Robert G. Wilson v_, Jul 07 2007 *)
%o (PARI) a(n) = if ((f=fibonacci(n))==1, 1, factor(f)[1,1]); \\ _Michel Marcus_, Nov 15 2014
%o (Magma) [1,1] cat [Minimum(PrimeDivisors(Fibonacci(n))): n in [3..70]]; // _Vincenzo Librandi_, Dec 25 2016
%Y Cf. A000045, A022307, A001605, A060319, A060320, A051694, A139044.
%K nonn
%O 1,3
%A _Labos Elemer_, Apr 03 2001
%E Better definition from _Omar E. Pol_, Apr 25 2008
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