A073958 Fibonacci numbers for which the number of prime factors (with multiplicity) is a Fibonacci number.

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 233, 377, 610, 987, 1597, 2584, 4181, 10946, 17711, 28657, 75025, 121393, 514229, 1346269, 3524578, 5702887, 9227465, 24157817, 39088169, 63245986, 165580141, 433494437

Offset: 1

Author

Felice Russo, Sep 03 2002

Keywords

• nice
• nonn

Comments

The prime Fibonacci numbers, A005478, are a subsequence.

Examples

			Example: 8=2*2*2, the number of prime factors is equal to 3, a Fibonacci number.
		

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..328

Crossrefs

Cf. A000045.

Programs

Mathematica

With[{fibs=Fibonacci[Range[0,50]]},Rest[Select[fibs,MemberQ[fibs, PrimeOmega[#]]&]]] (* Harvey P. Dale, Oct 27 2011 *)

PARI

isFibonacci(n)=my(k=n^2);k+=((k + 1) << 2);issquare(k) || (n > 0 && issquare(k-8))
select(n->isFibonacci(bigomega(n)), vector(99,i,fibonacci(i+1))) \\ Charles R Greathouse IV, Jun 17 2013