This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A074691 #27 Aug 21 2024 11:38:25 %S A074691 2,3,5,13,89,233,610,987,1597,10946,28657,514229,3524578,9227465, %T A074691 24157817,39088169,63245986,433494437,701408733,1134903170,1836311903, %U A074691 2971215073,7778742049,20365011074,365435296162,591286729879 %N A074691 Squarefree Fibonacci numbers with odd number of prime factors. %C A074691 Agrees for a long time with sequence of Fibonacci numbers whose number of divisors is a Fibonacci number. %H A074691 Amiram Eldar, <a href="/A074691/b074691.txt">Table of n, a(n) for n = 1..575</a> (terms 1..100 from T. D. Noe) %F A074691 Fibonacci(n) such that mu(Fibonacci(n)) = -1, where mu(n) is the Moebius mu function (A008683). %e A074691 610 belongs to the sequence because it has 3 prime factors (2, 5, 61); it also has 8 divisors (1, 2, 5, 10, 61, 122, 305, 610). %p A074691 with(combinat, fibonacci): m2_fib := proc(n); if (numtheory[mobius](fibonacci(n))=-1) then RETURN(fibonacci(n)); fi; end: seq(m2_fib(i), i=1..100); %t A074691 Select[Fibonacci[Range[80]], MoebiusMu[#] == -1 &] (* _Harvey P. Dale_, Aug 23 2011 *) %Y A074691 Subsequence of A061305 (squarefree Fibonacci numbers). %Y A074691 Cf. A000045. %Y A074691 Cf. A022307, A075735. %K A074691 easy,nice,nonn %O A074691 1,1 %A A074691 _Felice Russo_, Sep 03 2002 %E A074691 More terms from _Jani Melik_, Oct 07 2002