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Indices of Fibonacci numbers with 11 prime factors when counted with multiplicity.
2

%I #20 May 05 2024 19:19:57

%S 138,140,160,190,208,222,230,250,261,285,310,318,345,351,387,388,399,

%T 402,426,469,470,483,485,488,498,507,508,518,531,534,549,568,596,598,

%U 632,656,671,678,686,688,703,715,786,788,806,808,844,872,873,874,902

%N Indices of Fibonacci numbers with 11 prime factors when counted with multiplicity.

%H Amiram Eldar, <a href="/A114820/b114820.txt">Table of n, a(n) for n = 1..77</a>

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

%e a(1)=138 because the 138th Fibonacci number (i.e., 30960598847965113057878492344) consists of 11 prime factors (i.e., 2*2*2*137*139*461*691*829*18077*28657*1485571).

%t Select[Range[1000],PrimeOmega[Fibonacci[#]]==11&] (* _Harvey P. Dale_, Jan 09 2022 *)

%o (PARI) n=1;while(n<320,if(bigomega(fibonacci(n))==11,print1(n,", "));n++)

%Y Column k=11 of A303215.

%K hard,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Feb 19 2006

%E More terms from _Ryan Propper_, May 24 2006