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

1,2

Comments

The prime Fibonacci numbers, A005478, are a subsequence.

Links

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

Example

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

Mathematica

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

Prog

(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

Crossrefs

Cf. A000045.

Sequence in context: A177372 A109609 A274162 * A074317 A077371 A077372

Adjacent sequences: A073955 A073956 A073957 * A073959 A073960 A073961

Keyword

nice,nonn

Author

Felice Russo, Sep 03 2002

Status

approved