A114814 - OEIS

%I #21 May 05 2024 19:20:29

%S 18,44,45,57,63,68,69,76,91,98,111,118,124,125,134,141,169,172,183,

%T 185,201,202,203,213,218,229,247,253,267,302,303,329,335,347,363,371,

%U 373,377,381,382,386,395,398,413,415,439,443,461,497,501,529,547,563,579

%N Indices of Fibonacci numbers with 5 prime factors when counted with multiplicity.

%H Amiram Eldar, <a href="/A114814/b114814.txt">Table of n, a(n) for n = 1..112</a>

%H Blair Kelly, <a href="http://mersennus.net/fibonacci/">Fibonacci and Lucas Factorizations</a>.

%e a(1)=18 because 18th Fibonacci number (i.e., 2584) consists of 5 prime factors (i.e., 2*2*2*17*19).

%t t = {}; Do[f = FactorInteger[Fibonacci[n]]; If[Total[Transpose[f][[2]]] == 5, AppendTo[t, n]], {n, 2, 100}]; t (* _T. D. Noe_, Mar 14 2014 *)

%o (PARI) n=1;while(n<385,if(bigomega(fibonacci(n))==5,print1(n,", "));n++)

%Y Column k=5 of A303215.

%K nonn

%O 1,1

%A _Shyam Sunder Gupta_, Feb 19 2006

%E More terms from _Ryan Propper_, May 22 2006