cp's OEIS Frontend

A155916 Prime factors of odd Fibonacci numbers.

%I A155916 #7 Nov 21 2016 04:18:53
%S A155916 3,5,7,11,13,29,37,41,43,47,59,67,71,73,89,97,101,103,113,127,131,139,
%T A155916 149,151,157,163,179,191,193,199,223,233,239,251,263,269,277,281,283,
%U A155916 307,311,313,331,337,347,353,359,367,373,389,397,401,419,431,433,449
%N A155916 Prime factors of odd Fibonacci numbers.
%C A155916 Primes not in A133247.
%H A155916 Robert Israel, <a href="/A155916/b155916.txt">Table of n, a(n) for n = 1..10000</a>
%p A155916 filter:= proc(p) local a,b,i;
%p A155916 if not isprime(p) then return false fi;
%p A155916 a:= 0: b:= 1;
%p A155916 for i from 2 do
%p A155916   a,b:= b, (a+b) mod p;
%p A155916   if b = 0 then
%p A155916     if i mod 3 <> 0 then return true
%p A155916     elif a = 1 then return false
%p A155916     fi
%p A155916   fi
%p A155916 od:
%p A155916 end proc:
%p A155916 select(filter, [seq(i,i=3..1000,2)]); # _Robert Israel_, Nov 20 2016
%Y A155916 Cf. A014437, A133247.
%K A155916 nonn
%O A155916 1,1
%A A155916 _Tanya Khovanova_, Jan 30 2009