# [seqfan] Re: Can a repunit be a Fibonacci number?

israel at math.ubc.ca israel at math.ubc.ca
Fri May 13 19:21:10 CEST 2016

```Along the same lines, it seems likely that the only Fibonacci numbers whose
digits are sorted in ascending order are 1, 1, 2, 3, 5, 8, 13, 34, 55, 89,
144, 233, 377 and the only Fibonacci numbers whose digits are sorted in
descending order are 1, 1, 2, 3, 5, 8, 21, 55, 610, 987 (neither of these
are in OEIS, it seems).

Cheers,
Robert

On May 13 2016, Alonso Del Arte wrote:

>Sorting the base 10 digits of the Fibonacci numbers (A272918) does not
>really seem to go against what we know about Benford's law and the
>Fibonacci numbers. But if we sort the digits in descending order, it seems
>that, aside from the trivial initial exceptions, no term will start with
>the digit 1.
>
>Of course a base 10 repunit is not the only kind of number that would allow
>a Fibonacci number to be in this analogue to A272918. A Fibonacci number
>that has only 1s and 0s would then become something like 111111111000 in
>this sequence, but that seems unlikely as well.
>
>Al
>
>
```